Error Metadata file dll could not be found CSC when publishing

Question

I have a Visual studio solution with several projects in it, specifically a DotNet5 asp.net app, that has several netstandard 2.0 references on it. it builds and runs fine in the debugger but continuously throws the metadata errors. It keeps specifically referencing its looking for a net5 folder in the netstandard2 project. I cannot find where its getting this from, the problematic one used to be a multitargeted project against framework 4.7, 4.8, and net5.0, but i got annoyed with the multiple dll's and just migrated it to standard2.0 and had no issues till i want to publish it.

I've tried what a few other questions referenced, cleaning, rebuilding, remove and re add references to other projects, deleted the obj and bin folders out of the solution, the removing the sou file, tried VS 2019 (16.9.0 preview 2) preview vs 2019 (16.8.3) release, different computer (pulled back down from a lan git repository) and got the same error.... also tried searching the entire solution for references to net5.0 and didn't find it outside of the expected locations like the csproj for the asp.net project and its respective pubxml. And just for fun, I temporarily retargeted the library project back to net5.0 and it still threw the same error even when the exact file and path listed did exist.

Using enters for the error below for the different columns in the error message, and removed the "sensitive" info. There is no error code provided by Visual Studio. Anyone else got any more ideas on what to try?

Error

Metadata file 'C:\Users\UserName\source\repos\Solution\Project 2\bin\Release\net5.0\ref\Project 2.dll' could not be found.

Project 1

CSC

0

Edit: adding a couple other sections of the error messages:

1/2/2021 7:38:55 PM
System.AggregateException: One or more errors occurred. ---> Microsoft.WebTools.Shared.Exceptions.WebToolsException: Build failed. Check the Output window for more details.
   --- End of inner exception stack trace ---
---> (Inner Exception #0) Microsoft.WebTools.Shared.Exceptions.WebToolsException: Build failed. Check the Output window for more details.<---

Microsoft.WebTools.Shared.Exceptions.WebToolsException: Build failed. Check the Output window for more details.

===================

And the end of the output window since full thing is a bit too long. still can't figure out where its getting the net5.0 for the one project reference

/reference:C:\Users\UserName\.nuget\packages\system.xml.xpath.xmldocument\4.0.1\ref\netstandard1.3\System.Xml.XPath.XmlDocument.dll /reference:C:\Users\UserName\.nuget\packages\mysql.data\8.0.22\lib\net5.0\Ubiety.Dns.Core.dll /reference:"C:\Users\UserName\source\repos\CheckNotes\Project 3\bin\Release\netstandard2.0\Project 3.dll" /reference:"C:\Users\UserName\source\repos\CheckNotes\Project 2\bin\Release\net5.0\ref\Project 2.dll" /reference:C:\Users\UserName\source\repos\CheckNotes\Project 4\bin\Release\netstandard2.0\Project 4.dll /reference:"C:\Program Files\dotnet\packs\Microsoft.NETCore.App.Ref\5.0.0\ref\net5.0\WindowsBase.dll" /reference:C:\Users\UserName\.nuget\packages\mysql.data\8.0.22\lib\net5.0\Zstandard.Net.dll /debug+ /debug:portable /filealign:512 /optimize+ /out:"obj\Release\net5.0\CheckNotes Web - Core.dll" /refout:"obj\Release\net5.0\ref\CheckNotes Web - Core.dll" /target:exe /warnaserror- /utf8output /deterministic+ /langversion:9.0 /analyzerconfig:"obj\Release\net5.0\CheckNotes Web - Core.GeneratedMSBuildEditorConfig.editorconfig" /analyzerconfig:"C:\Program Files\dotnet\sdk\5.0.200-preview.20601.7\Sdks\Microsoft.NET.Sdk\analyzers\build\config\AnalysisLevel_5_Default.editorconfig" /analyzer:"C:\Program Files\dotnet\sdk\5.0.200-preview.20601.7\Sdks\Microsoft.NET.Sdk.Web\analyzers\cs\Microsoft.AspNetCore.Analyzers.dll" /analyzer:"C:\Program Files\dotnet\sdk\5.0.200-preview.20601.7\Sdks\Microsoft.NET.Sdk.Web\analyzers\cs\Microsoft.AspNetCore.Mvc.Analyzers.dll" /analyzer:"C:\Program Files\dotnet\sdk\5.0.200-preview.20601.7\Sdks\Microsoft.NET.Sdk.Web\analyzers\cs\Microsoft.AspNetCore.Components.Analyzers.dll" /analyzer:"C:\Program Files\dotnet\sdk\5.0.200-preview.20601.7\Sdks\Microsoft.NET.Sdk\targets\..\analyzers\Microsoft.CodeAnalysis.CSharp.NetAnalyzers.dll" /analyzer:"C:\Program Files\dotnet\sdk\5.0.200-preview.20601.7\Sdks\Microsoft.NET.Sdk\targets\..\analyzers\Microsoft.CodeAnalysis.NetAnalyzers.dll" Controllers\AssemblyController.cs Controllers\CheckNotesController.cs Controllers\ContactsController.cs Controllers\CustomerController.cs Controllers\HomeController.cs Controllers\ImageController.cs Controllers\OperatorPagesController.cs Controllers\PalletsController.cs Controllers\SharedController.cs Controllers\StatisticsController.cs Models\ControllerClass\ctrlrAssembly.cs Models\ControllerClass\CtrlrCheckNotes.cs Models\ControllerClass\ctrlrContacts.cs Models\ControllerClass\CtrlrCustomer.cs Models\ControllerClass\CtrlrOperatorPages.cs Models\ControllerClass\CtrlrPallet.cs Models\ControllerClass\ctrlrStats.cs Models\DataClass\AppSettings.cs Models\ErrorViewModel.cs Models\renderAction.cs Program.cs Startup.cs "obj\Release\net5.0\.NETCoreApp,Version=v5.0.AssemblyAttributes.cs" "obj\Release\net5.0\CheckNotes Web - Core.AssemblyInfo.cs" "obj\Release\net5.0\CheckNotes Web - Core.RazorAssemblyInfo.cs" /warnaserror+:NU1605
CSC(0,0): Error CS0006: Metadata file 'C:\Users\UserName\source\repos\CheckNotes\Project 2\bin\Release\net5.0\ref\Project 2.dll' could not be found

10>Build failed. Check the Output window for more details.
========== Build: 9 succeeded, 0 failed, 0 up-to-date, 0 skipped ==========
========== Publish: 0 succeeded, 1 failed, 0 skipped ==========

Answer 1

Got it to publish but I am so confused....something to do with the publish profile. If i delete that and generate a new one, works fine. as soon as i edit it using the GUI, broken....generate it again. So far seems ok to edit it manually but TBD. not sure if the "fix" will survive restarting Visual studio or not.

Edit - Scratch that, found the difference. Remove the following line in Properties/FolderProfile.pubxml and it's fine.

<TargetFramework>net5.0</TargetFramework>