System.AggregateException: One or more errors occurred. ---> System.InvalidOperationException: Last write time for 'C:\Users\jugki\source\repos\BlazorApp1\BlazorApp1\wwwroot\app.css' is not defined. at Microsoft.AspNetCore.StaticWebAssets.Tasks.StaticWebAsset.Validate() at Microsoft.AspNetCore.StaticWebAssets.Tasks.StaticWebAsset.FromTaskItem(ITaskItem item) at Microsoft.AspNetCore.StaticWebAssets.Tasks.DefineStaticWebAssetEndpoints.ParallelWorker.Process(Int32 i, ParallelLoopState _) at Microsoft.AspNetCore.StaticWebAssets.Tasks.DefineStaticWebAssetEndpoints.<>c.<Execute>b__16_2(Int32 i, ParallelLoopState loop, ParallelWorker state) at System.Threading.Tasks.Parallel.<>c__DisplayClass17_0`1.<ForWorker>b__1() at System.Threading.Tasks.Task.InnerInvokeWithArg(Task childTask) at System.Threading.Tasks.Task.<>c__DisplayClass176_0.<ExecuteSelfReplicating>b__0(Object <p0>) --- End of inner exception stack trace --- at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions) at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken) at System.Threading.Tasks.Parallel.ForWorker[TLocal](Int32 fromInclusive, Int32 toExclusive, ParallelOptions parallelOptions, Action`1 body, Action`2 bodyWithState, Func`4 bodyWithLocal, Func`1 localInit, Action`1 localFinally) at System.Threading.Tasks.Parallel.For[TLocal](Int32 fromInclusive, Int32 toExclusive, Func`1 localInit, Func`4 body, Action`1 localFinally) at Microsoft.AspNetCore.StaticWebAssets.Tasks.DefineStaticWebAssetEndpoints.Execute() at Microsoft.Build.BackEnd.TaskExecutionHost.Execute() at Microsoft.Build.BackEnd.TaskBuilder.<ExecuteInstantiatedTask>d__26.MoveNext()---> (Inner Exception #0) System.InvalidOperationException: Last write time for 'C:\Users\jugki\source\repos\BlazorApp1\BlazorApp1\wwwroot\app.css' is not defined. at Microsoft.AspNetCore.StaticWebAssets.Tasks.StaticWebAsset.Validate() at Microsoft.AspNetCore.StaticWebAssets.Tasks.StaticWebAsset.FromTaskItem(ITaskItem item) at Microsoft.AspNetCore.StaticWebAssets.Tasks.DefineStaticWebAssetEndpoints.ParallelWorker.Process(Int32 i, ParallelLoopState _) at Microsoft.AspNetCore.StaticWebAssets.Tasks.DefineStaticWebAssetEndpoints.<>c.<Execute>b__16_2(Int32 i, ParallelLoopState loop, ParallelWorker state) at System.Threading.Tasks.Parallel.<>c__DisplayClass17_0`1.<ForWorker>b__1() at System.Threading.Tasks.Task.InnerInvokeWithArg(Task childTask) at System.Threading.Tasks.Task.<>c__DisplayClass176_0.<ExecuteSelfReplicating>b__0(Object <p0>)<------> (Inner Exception #1) System.InvalidOperationException: Last write time for 'C:\Users\jugki\source\repos\BlazorApp1\BlazorApp1\wwwroot\lib\bootstrap\dist\css\bootstrap-grid.css.map' is not defined. at Microsoft.AspNetCore.StaticWebAssets.Tasks.StaticWebAsset.Validate() at Microsoft.AspNetCore.StaticWebAssets.Tasks.StaticWebAsset.FromTaskItem(ITaskItem item) at Microsoft.AspNetCore.StaticWebAssets.Tasks.DefineStaticWebAssetEndpoints.ParallelWorker.Process(Int32 i, ParallelLoopState _) at Microsoft.AspNetCore.StaticWebAssets.Tasks.DefineStaticWebAssetEndpoints.<>c.<Execute>b__16_2(Int32 i, ParallelLoopState loop, ParallelWorker state) at System.Threading.Tasks.Parallel.<>c__DisplayClass17_0`1.<ForWorker>b__1() at System.Threading.Tasks.Task.InnerInvokeWithArg(Task childTask) at System.Threading.Tasks.Task.<>c__DisplayClass176_0.<ExecuteSelfReplicating>b__0(Object <p0>)<------> (Inner Exception #2) System.InvalidOperationException: Last write time for 'C:\Users\jugki\source\repos\BlazorApp1\BlazorApp1\wwwroot\lib\bootstrap\dist\css\bootstrap-grid.rtl.css' is not defined. at Microsoft.AspNetCore.StaticWebAssets.Tasks.StaticWebAsset.Validate() at Microsoft.AspNetCore.StaticWebAssets.Tasks.StaticWebAsset.FromTaskItem(ITaskItem item) at Microsoft.AspNetCore.StaticWebAssets.Tasks.DefineStaticWebAssetEndpoints.ParallelWorker.Process(Int32 i, ParallelLoopState _) at Microsoft.AspNetCore.StaticWebAssets.Tasks.DefineStaticWebAssetEndpoints.<>c.<Execute>b__16_2(Int32 i, ParallelLoopState loop, ParallelWorker state) at System.Threading.Tasks.Parallel.<>c__DisplayClass17_0`1.<ForWorker>b__1() at System.Threading.Tasks.Task.InnerInvokeWithArg(Task childTask) at System.Threading.Tasks.Task.<>c__DisplayClass176_0.<ExecuteSelfReplicating>b__0(Object <p0>)<---I created a new .NET Web App project using Visual Studio 2022 (e.g., ASP.NET Core Web App, Razor Pages, Blazor WebAssembly, etc. using .NET 8).The project builds fail immediately with the error:
"The 'DefineStaticWebAssetEndpoints' task failed unexpectedly.System.InvalidOperationException: Last write time is not defined for some files in wwwroot/lib/."
This happens even before I add any code or packages. I’ve tried:
- Changing the project location to D:\Projects (outside OneDrive)
- Disabling Git integration
- Clearing all template caches and resetting VS template paths
- Ensuring .NET 8 SDK is fully updated
None of these steps resolve the issue. It seems to relate to how static web assets (e.g., .map, .css, .js files) are generated with missing LastWriteTime metadata.
Expected: The project should build successfully right after creation with the default template.
Actual: Build fails with StaticWebAssets task errors.
Any ideas or workarounds would be appreciated.