When Tools/Debugger/DataTips/Override VS DataTips with ReSharper DataTips is enabled if you hover over the property of an object (for example, the .Count property of a collection) you will receive this in the tooltip:
error BC30451: 'Count' is not declared. It may be inaccessible due to its protection level.
However, if you hover over only the first letter of the property, you get the property's value.

Example code to reproduce:

Module Program
    Sub Main(args As String())
        Dim salmons As New List(Of String)
        salmons.Add("chinook")
        salmons.Add("coho")
        salmons.Add("pink")
        salmons.Add("sockeye")
        If (salmons.Count > 0) Then
            For Each salmon As String In salmons
                Console.Write(salmon & " ")
            Next
        End If

    End Sub
End Module

Hello,
I am having problems with R# data tips with some variables.

Tooltip shows: BC30451: variable is not declared. It may be inaccessible due to its protection level."
VS2017 shows the same value without problems.
See the screenshot.

/ Best regards

The feature described first in https://blog.jetbrains.com/dotnet/2017/11/21/resharper-2017-3-brings-debugger-editor/ has a bug. If there are many locals displayed a part of the info vanished on the right. Could you extend the scrollbar so you can see all info? Cheers!

Evaluator: False
OS Version: Microsoft Windows NT 10.0.17763.0
Product: ReSharper, Version: 2018.3.20190304.45354
Time Zone: Mitteleuropäische Zeit

Description
Working with VS2019 RC2 Enterprise. I have a solution which uses NHibernate to access a local SQL-Server database. The performance on processing LINQ queries is bad, when i debug in single step mode (via F10). First time i step through the performance is good. The second time i step through the same method it takes much longer until the rstatement is processed. Also VS seems to hang while processing the return statement.

Here is a sample LINQ statement:

public Price GetPriceForAccountingMonth(ISession transactionSession, Price pCriteria)
{
try
{
int? cavernId = TransformCavernId(pCriteria.CavernId);

var query = transactionSession.Query<Price>();
var result = (from x in query
       where x.Id.Version == pCriteria.Id.Version
          && x.Id.Year == pCriteria.Id.Year
          && x.Id.Month == pCriteria.Id.Month
          && x.PriceTypeDB == pCriteria.PriceTypeDB
          && x.StorageId == pCriteria.StorageId
          && x.CavernId == cavernId
          && (x.ApprovalStateDB == pCriteria.ApprovalStateDB || pCriteria.ApprovalState == ApprovalStates.Incomplete)
          orderby x.Id.SerialNumber descending 
       select x).FirstOrDefault();
return result;

}
catch(Exception e)
{
GlobalConfig.Instance.LogError(string.Format(ErrorMessages.ErrQueryDataFailed, "PriceDataService", "GetPriceForAccountingMonth"), e);
throw new QueryFailedException("PriceDataService", "GetPriceForAccountingMonth", e);
}
}

ReSharperPlatformVs15 Wave 191 Hive _eff7ddd8 — JetBrains ReSharper Ultimate 2019.1 EAP 1 D Build 191.0.20190226.43309-eap01d

JetBrains dotCover 2019.1 EAP 1 D Build 2019.1.20190226.75059-eap01d
JetBrains dotMemory 2019.1 EAP 1 D Build 2019.1.20190226.75112-eap01d
JetBrains dotTrace 2019.1 EAP 1 D Build 2019.1.20190226.75115-eap01d
JetBrains ReSharper 2019.1 EAP 1 D Build 2019.1.20190226.74511-eap01d
JetBrains ReSharper C++ 2019.1 EAP 1 D Build 2019.1.20190226.74528-eap01d
JetBrains TeamCity Add-in 2019.1 EAP 1 D Build 2019.1.20190226.74524-eap01d

Trying to start stack trace update request with Status Rejected

--- EXCEPTION #1/1 [LoggerException]
Message = “Trying to start stack trace update request with Status Rejected”
ExceptionPath = Root
ClassName = JetBrains.Util.LoggerException
Data.ManagedThreadName = <NULL>
Data.SccRevisionShell = “<there are no packages matching the criteria>”
Data.HostProductInfo = “JetBrains ReSharper Ultimate 2019.1 EAP 1 D Build 191.0.20190226.43309-eap01d”
Data.SubProducts.#0 = “JetBrains dotCover 2019.1 EAP 1 D Build 2019.1.20190226.75059-eap01d”
Data.SubProducts.#1 = “JetBrains dotTrace 2019.1 EAP 1 D Build 2019.1.20190226.75115-eap01d”
Data.SubProducts.#2 = “JetBrains ReSharper C++ 2019.1 EAP 1 D Build 2019.1.20190226.74528-eap01d”
Data.SubProducts.#3 = “JetBrains TeamCity Add-in 2019.1 EAP 1 D Build 2019.1.20190226.74524-eap01d”
Data.SubProducts.#4 = “JetBrains ReSharper 2019.1 EAP 1 D Build 2019.1.20190226.74511-eap01d”
Data.SubProducts.#5 = “JetBrains dotMemory 2019.1 EAP 1 D Build 2019.1.20190226.75112-eap01d”
Data.SccRevisionEnv = “
Platform\Core\Shell:
git::refs/heads/191::4cfd8145c936e1159394d0f187b814f6c9c9e297

Platform\VisualStudio:
git::refs/heads/191::34de08c8f8d278b1f3e33a25a2be84c66a9a680c
”
Data.VsVersion = 15.9.28307.423
HResult = COR_E_APPLICATION=80131600
StackTraceString = “
at JetBrains.Util.Logging.Logger.Fail(String messageText)
at JetBrains.ReSharper.Feature.Services.StackTraces.StackTrace.StackTraceUpdateStateToken.Start()
at JetBrains.ReSharper.Feature.Services.StackTraces.StackTrace.StackTraceHighlightTextReadActivity.Start()
at JetBrains.Application.Threading.InterruptableReadActivity.DoStart()
at JetBrains.ReSharper.Feature.Services.StackTraces.StackTrace.StackTraceUpdateManager.StartNextRequest(StackTraceUpdateStateToken token)
at JetBrains.ReSharper.Feature.Services.StackTraces.StackTrace.StackTraceHighlightTextReadActivity.<OnInterrupt>b__26_0()
at JetBrains.Threading.TimedActionsHost.TimedAction.Execute()
at JetBrains.Threading.ReentrancyGuard.Execute(String name, Action action)
at JetBrains.Threading.ReentrancyGuard.ExecutePendingActions()
at JetBrains.Threading.JetDispatcher.Closure.Execute()
at JetBrains.Util.Concurrency.WinJetDispatcher.ProcessQueue(Int32 nMinBucket)
at JetBrains.Util.Concurrency.WinJetDispatcher.<>c__DisplayClass18_0.<BeginInvokeCore>b__0()
at System.Windows.Threading.DispatcherOperation.InvokeDelegateCore()
at System.Windows.Threading.DispatcherOperation.InvokeImpl()
at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state)
at MS.Internal.CulturePreservingExecutionContext.CallbackWrapper(Object obj)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at MS.Internal.CulturePreservingExecutionContext.Run(CulturePreservingExecutionContext executionContext, ContextCallback callback, Object state)
at System.Windows.Threading.DispatcherOperation.Invoke()
at System.Windows.Threading.Dispatcher.ProcessQueue()
at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
”

ReSharperPlatformVs16 Wave 191 Hive _dd58879f — JetBrains ReSharper Ultimate 2019.1 EAP 5 Build 191.0.20190404.123435-eap05

JetBrains ReSharper 2019.1 EAP 5 Build 2019.1.20190404.125914-eap05

Collection was modified; enumeration operation may not execute.

--- EXCEPTION #1/2 [InvalidOperationException]
Message = “Collection was modified; enumeration operation may not execute.”
ExceptionPath = Root.InnerException
ClassName = System.InvalidOperationException
HResult = COR_E_INVALIDOPERATION=80131509
Source = mscorlib
StackTraceString = “
at System.ThrowHelper.ThrowInvalidOperationException(ExceptionResource resource)
at System.Collections.Generic.List1.Enumerator.MoveNextRare() at System.Collections.Generic.List1.Enumerator.MoveNext()
at JetBrains.ReSharper.Feature.Services.StackTraces.StackTrace.StackTraceVisitor.VisitCompositeNode(CompositeNode node)
at JetBrains.ReSharper.Feature.Services.StackTraces.StackTrace.StackTraceHighlightTextReadActivity.Work()
at JetBrains.Application.Threading.InterruptableReadActivity.DoWork()
at JetBrains.Application.Threading.InterruptableReadActivity.WorkerThreadProc()
at JetBrains.Util.Logging.Logger.Catch(Action action)
”

--- Outer ---

--- EXCEPTION #2/2 [LoggerException]
Message = “Collection was modified; enumeration operation may not execute.”
ExceptionPath = Root
ClassName = JetBrains.Util.LoggerException
Data.ManagedThreadName = “JetPool(S) #3”
Data.LastExtension = cs
Data.SccRevisionShell = “<there are no packages matching the criteria>”
Data.HostProductInfo = “JetBrains ReSharper Ultimate 2019.1 EAP 5 Build 191.0.20190404.123435-eap05”
Data.SubProducts.#0 = “JetBrains ReSharper 2019.1 EAP 5 Build 2019.1.20190404.125914-eap05”
Data.SccRevisionEnv = “
Platform\Core\Shell:
git::refs/heads/191-eap5::adaf4c187394e8007c0374d03a1720ce06f0a134

Platform\VisualStudio:
git::refs/heads/191-eap5::a80948ed6b5fb3b392e44e0db9ca1cbed720d115
”
Data.VsVersion = 16.0.28729.10
InnerException = “Exception #1 at Root.InnerException”
HResult = COR_E_APPLICATION=80131600
StackTraceString = “
at JetBrains.Util.Logging.Logger.Catch(Action action)
at JetBrains.Application.Threading.Tasks.TaskHostEx.<>c__DisplayClass2_0.<RunSafe>b__0()
at JetBrains.Application.Threading.Tasks.TaskHost.AccessViolationCatcher(Action action)
at JetBrains.Application.Threading.Tasks.TaskHost.<>c__DisplayClass39_0.<Create>b__1(Object state)
at System.Threading.Tasks.Task.InnerInvoke()
at System.Threading.Tasks.Task.Execute()
at System.Threading.Tasks.Task.ExecutionContextCallback(Object obj)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot)
at System.Threading.Tasks.Task.ExecuteEntry(Boolean bPreventDoubleExecution)
at System.Threading.Tasks.TaskScheduler.TryExecuteTask(Task task)
at JetBrains.Application.Threading.Tasks.Scheduler.JetScheduler.ExecuteTask(Task task)
at JetBrains.Application.Threading.Tasks.Scheduler.JetSchedulerThread.EnqueueNextTask()
at JetBrains.Application.Threading.Tasks.Scheduler.JetSchedulerThread.ThreadPoolProc()
at ANNOTATED: JetBrains.Application.Threading.Tasks.Scheduler.JetSchedulerThread #3.JetPool(S) #3(Action )
at JetBrains.Util.Reflection.CallStackAnnotation.InvokeAnnotated(String classNameOfNewFrame, String methodNameOfNewFrame, Action actionToAnnotate)
at JetBrains.Util.Reflection.CallStackAnnotation.CatchAnnotatedInvocation[TClassOfNewFrame](String methodNameOfNewFrame, Action actionToAnnotate)
at JetBrains.Application.Threading.Tasks.Scheduler.JetSchedulerThread.<Start>b__20_0()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
”

It is sometimes useful to have a large partial class with many tests split across several files. When performing operations at the class level (e.g. create session), Rider adds issues from the entire class and not just the partial files clicked.

In many cases, a base class containing test cases is extended for specific implementations. Some tests are overridden in the extending class, while others aren't, based on needs. In both the unit test explorer and session tabs, it seems that first the tests defined (i.e. overridden) on the subclass are shown, followed by those from the superclass; the latter are also prefixed with the name of the superclass. This makes it quite difficult to navigate and find tests, as one must know whether a specific test was overriden or not. It seems that a simple alphabetical sort would work best here (at least optionally).

Similarly, it seems that with xunit, facts (simple tests) are sorted before theories. This again seems like a detail that shouldn't be very relevant for finding the test in the tabs.

When trying to launch in Rider NUnit tests with equal names but with different type arguments - all tests are executed (reachable in debugger) but only one test is shown (even in "Explorer").
RSRP-419137 and DCVR-6894 might be related, however they are resolved and the bug is still reachable.

On Large Solutions when Filenames occures Multiple times in the same Solution cleanupcode.exe crashes or hangs with > 30gb memory consumption

I am not Shure but the problems most times occures on files like "AssemblyInfo.cs", "Programm.cs", "Reference.cs" or other often used Filenames.

First there comes a lot of warnings about inconsitent caches
Later there comes more and more Exceptions on files with inconsitent caches

then memory consumption getting higher and higher and then it crashes completely.

Console looks like

<WindowsServices>\<Project1>\Properties\AssemblyInfo.cs
Warning: Inconsistent caches for file AssemblyInfo.cs: cached=1416 actual=1513. Please, describe how this file could be changed.
...
<WindowsServices>\<Project2>\Properties\AssemblyInfo.cs
Warning: Inconsistent caches for file AssemblyInfo.cs: cached=1394 actual=1491. Please, describe how this file could be changed.
...
<WindowsServices>\<Project3>\Properties\AssemblyInfo.cs - JavaScript decoration
Warning: Inconsistent caches for file AssemblyInfo.cs: cached=1408 actual=1505. Please, describe how this file could be changed.
...
<WindowsServices>\<Project30>\Connected Services\FooService\Reference.cs - Applying code style
Warning: Inconsistent caches for file Reference.cs: cached=226402 actual=296540. Please, describe how this file could be changed.
...
<WindowsServices>\<Project30>\Connected Services\FooService\Reference.cs
StartIndex darf nicht kleiner als Null sein. Parametername: startIndex

--- EXCEPTION #1/2 [ArgumentOutOfRangeException]
Message = "StartIndex darf nicht kleiner als Null sein."
ExceptionPath = Root.InnerException
ClassName = System.ArgumentOutOfRangeException
Data.ThreadLocalDebugInfo = "Code Cleanup"
HResult = COR_E_ARGUMENTOUTOFRANGE=80131502
Source = mscorlib
ParamName = startIndex
StackTraceString = "
  bei System.String.Substring(Int32 startIndex, Int32 length)
     bei JetBrains.Text.StringBuffer.GetText(TextRange range)
     bei JetBrains.Text.ProjectedBuffer.GetText(TextRange range)
     bei JetBrains.ReSharper.Psi.CSharp.Parsing.CSharpTokenType.IdentifierNodeType.Create(IBuffer buffer, TreeOffset startOffset, TreeOffset endOffset
)
     bei JetBrains.ReSharper.Psi.CSharp.Parsing.CSharpMissingTokensInserter.ProcessLeafElement(TreeElement root)
     bei JetBrains.ReSharper.Psi.Parsing.MissingTokenInserterBase.Run(TreeElement root)
     bei JetBrains.ReSharper.Psi.CSharp.Parsing.CSharpMissingTokensInserter.Run(TreeElement node, ILexer lexer, ITokenOffsetProvider offsetProvider, B
oolean trimTokens, PreProcessorParser preProcessorParser, SeldomInterruptChecker interruptChecker, ITokenIntern tokenIntern)
     bei JetBrains.ReSharper.Psi.CSharp.Parsing.CSharpParser.InsertMissingTokens(TreeElement result, Boolean trimMissingTokens)
     bei JetBrains.ReSharper.Psi.CSharp.Parsing.CSharpParser.ParseCodeBlock()
     bei JetBrains.ReSharper.Psi.ExtensionsAPI.Tree.ClosedChameleonElement.TryParseUsingTokenBuffer(Func`2 parseFunc)
     bei JetBrains.ReSharper.Psi.ExtensionsAPI.Tree.ClosedChameleonElement.Parse(Func`2 parseFunc)
     bei JetBrains.ReSharper.Psi.CSharp.Impl.Tree.ChameleonBlock.OpenChameleon()
     bei JetBrains.ReSharper.Psi.CSharp.Impl.Tree.ChameleonBlock.get_FirstChild()
     bei JetBrains.ReSharper.Psi.Util.TreeRange.NodeIterator(ITreeRange range, Func`2 predicate)
     bei JetBrains.ReSharper.Psi.Util.RegionStructureBuilder.BuildRegionStructure(ITreeNode node, INodeTreeNavigator treeNodeNavigator)
     bei JetBrains.ReSharper.Psi.CSharp.Impl.CodeStyle.MemberReordering.MemberReorderingProcessor.Process(ITreeNode node)
     bei JetBrains.ReSharper.Psi.CSharp.CodeStyle.CSharpFormatterHelper.ReorderMembers(ICSharpTypeAndNamespaceHolderDeclaration declaration)
     bei JetBrains.ReSharper.Psi.Transactions.PsiTransactions.Execute(String commandName, Action handler)

When trying to skip a specific xunit test case by placing a Skip value on an InlineData attribute, the test is executed anyway.

Source code:

public class UnitTest1
{
    [Theory]
    [InlineData(true, Skip = "Don't run")]  // This is ignored
    [InlineData(false)]
    public void Foo(bool param)
    {
        if (param)
            throw new Exception("Never supposed to happen");
    }
}

csproj:

<Project Sdk="Microsoft.NET.Sdk">

    <PropertyGroup>
        <TargetFramework>netcoreapp3.0</TargetFramework>

        <IsPackable>false</IsPackable>
    </PropertyGroup>

    <ItemGroup>
        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.0.1"/>
        <PackageReference Include="xunit" Version="2.4.0"/>
        <PackageReference Include="xunit.runner.visualstudio" Version="2.4.0"/>
    </ItemGroup>

</Project>

Test is properly skipped when running on the command line:

> dotnet test
Test run for /home/roji/projects/Test/bin/Debug/netcoreapp3.0/Test.dll(.NETCoreApp,Version=v3.0)
Microsoft (R) Test Execution Command Line Tool Version 16.1.1
Copyright (c) Microsoft Corporation.  All rights reserved.

Starting test execution, please wait...
                                                                                                                                                                                                                   
[xUnit.net 00:00:00.47]     Test.UnitTest1.Foo(param: True) [SKIP]
                                                                                                                                                                                                                   
  ! Test.UnitTest1.Foo(param: True) [1ms]
                                                                                                                                                                                                                   
Test Run Successful.
Total tests: 2
     Passed: 1
    Skipped: 1
 Total time: 1.0950 Seconds

JetBrains Rider 2019.1 Build RD-191.6062.106 Date 2019-03-09T05:35:10.205+0000

--- EXCEPTION #1/1 [LoggerException]
Message = “Item 43810 had old key value <Uncategorized>, but was not registered in cache OptimizedPersistentSortedMap2 by this value.” ExceptionPath = Root ClassName = JetBrains.Util.LoggerException HResult = COR_E_APPLICATION=80131600 StackTraceString = “ at JetBrains.Util.Logging.Logger.Fail(String messageText) at JetBrains.ReSharper.UnitTestFramework.Caches.PersistentSortedMapExtension.RemoveFromSetBy[TKey,TItem](OptimizedPersistentSortedMap2 map, TKey key, TItem item)
at JetBrains.ReSharper.UnitTestFramework.Caches.OneToSetLevelDbCache1.ElementRemoved(IEnumerable1 elements)
at JetBrains.ReSharper.UnitTestFramework.UnitTestElementRepository.Remove(ICollection1 elements) at JetBrains.ReSharper.UnitTestFramework.Elements.UnitTestElementManager.RemoveElementsNoRaise(ISet1 elements, ISet1 changedElements) at JetBrains.ReSharper.UnitTestFramework.Elements.UnitTestElementManager.ApplyChanges(IUnitTestElementsObserver observer) at JetBrains.ReSharper.UnitTestFramework.Exploration.UnitTestArtifactExplorationRunner.<ExploreProject>d__9.MoveNext() at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx) at System.Runtime.CompilerServices.AsyncMethodBuilderCore.MoveNextRunner.Run() at System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(Action action, Boolean allowInlining, Task& currentTask) at System.Threading.Tasks.Task.FinishContinuations() at System.Threading.Tasks.Task1.TrySetResult(TResult result)
at System.Threading.Tasks.TaskCompletionSource`1.TrySetResult(TResult result)
at JetBrains.ReSharper.UnitTestFramework.Extensions.TaskExtensions.<>c__DisplayClass8_0.<Finally>b__0(Task t)
at System.Threading.Tasks.Task.Execute()
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot)
at System.Threading.Tasks.Task.ExecuteEntry(Boolean bPreventDoubleExecution)
at System.Threading.ThreadPoolWorkQueue.Dispatch()
”

last.action = null

app.eap = true
app.internal = true
app.build = RD-191.6062.106
app.version.major = 2019
app.version.minor = 1
app.build.date = 2019-03-09T05:35:10.205+0000
app.build.date.release = 2019-04-20T00:00:10.205+0000
app.build.date.release = 2019-04-20T00:00:10.205+0000
app.compilation.timestamp = null
app.product.code = RD

os.name = Windows 10
java.version = 1.8.0_202-release
java.vm.vendor = JetBrains s.r.o

UIUtil.isRetina = false
JBUI.isHiDPI() = false
ImageScaleFactor = 1

Rider isn't consistently placing opening and closing curly braces on new lines after the "@" respective char in Razor pages. Here are some code examples:

Here, the opening brace is placed in the same column below the "@" sign (correct):

    @if (Model.Header != null)
    {
        <div class="OuterTableHeader" colspan="2">@Model.Header</div>
    }

Here, the first opening brace is placed below the "@" sign in front of the "if" statement (correct), but it isn't in the inner block in front of the "foreach" statement (incorrect):

        @if (Model.HiddenFields != null)
        {
            @foreach (string field in Model.HiddenFields)
             {
                 <input type="hidden" name="@(field)Prev" value="@Value(field)">
             }
        }

Here, it's the opposite of the last example. The "@@foreach" statement is correct but the "@if" statement isn't:

            @foreach (Row x in Model.Rows)
            {
                @if (!x.Key.Display)
                 {
                     continue;
                 }