Asp.Net Core 5 scaffolded items incompatibility

[Bryan]

Hi,

I'm trying to create an ASP.NET Core version 5.0 application using MVC, Telerik UI for ASP.NET Core version 2020.3.1118, and with individual user accounts (ASP.NET Identity) authentication. I need to add scaffolded items to customize the ASP.NET Identity Pages. It seems that this release of the Telerik UI for ASP.NET Core package is incompatible with scaffolded items for ASP.NET Identity Pages. The errors I get depend on which order I do things in.

Scenario 1: First I create the app (with individual user accounts authentication). Next I add the Telerik.UI.for.AspNet.Core version 2020.3.118 package using the manage NuGet packages for solution menu item. Then I attempt to add a new scaffolded item for Identity. VS2019 gives me an error message dialog box that says:

There was an error running the selected code generator: 'Package restore failed. Rolling back package changes for 'WebApplication1'.'

Scenario 2: First I create the app (with individual user accounts authentication). Next I select the context menu item to add new scaffolded item, select Identity, click Add, wait for package changes to happen, and then cancel out of adding a new scaffolded item. Then I attempt to add the Telerik.UI.for.AspNet.Core version 2020.3.118 package using the manage NuGet packages for solution menu item. That fails and I get the following in my error list:

SeverityCodeDescriptionProjectFileLineSuppression State
ErrorNU1107Version conflict detected for Microsoft.CodeAnalysis.CSharp.Workspaces. Install/reference Microsoft.CodeAnalysis.CSharp.Workspaces 3.8.0 directly to project WebApplication1 to resolve this issue. 
 WebApplication1 -> Microsoft.VisualStudio.Web.CodeGeneration.Design 5.0.1 -> Microsoft.VisualStudio.Web.CodeGenerators.Mvc 5.0.1 -> Microsoft.VisualStudio.Web.CodeGeneration 5.0.1 -> Microsoft.VisualStudio.Web.CodeGeneration.EntityFrameworkCore 5.0.1 -> Microsoft.VisualStudio.Web.CodeGeneration.Core 5.0.1 -> Microsoft.VisualStudio.Web.CodeGeneration.Templating 5.0.1 -> Microsoft.VisualStudio.Web.CodeGeneration.Utils 5.0.1 -> Microsoft.CodeAnalysis.CSharp.Workspaces (>= 3.8.0) 
 WebApplication1 -> Telerik.UI.for.AspNet.Core 2020.3.1118 -> Microsoft.CodeAnalysis 3.3.1 -> Microsoft.CodeAnalysis.CSharp.Workspaces (= 3.3.1).WebApplication1C:\Users\bmorris\source\repos\WebApplication1\WebApplication1\WebApplication1.csproj1

SeverityCodeDescriptionProjectFileLineSuppression State
ErrorPackage restore failed. Rolling back package changes for 'WebApplication1'.

It seems that scaffolded items want to use Microsoft.CodeAnalysis.CSharp.Workspaces version 3.8 and Telerik.UI.for.AspNet.Core wants to use version 3.3.1 and the version are incompatible. Do you have a solution for this now or on the horizon?

Thanks.

[Bryan]

BTW, I forgot to mention that this problem did not occur in a recent project I did that used ASP.NET Core version 3.1.

[Misho]

Hello,

We have a troubleshooting article which is related to this issue: https://docs.telerik.com/aspnet-core/troubleshoot/troubleshooting-net5 In addition we've just released the new major release R1 2021 so I recommend you to upgrade to it and give it a shot. 

Looking forward to your feedback!

Regards,
Misho
Progress Telerik