Identity scaffolding in .net core 6.0 gives error message "Length cannot be less than zero."

Question

Hello,

I've been trying to scaffold various Identity pages, however I keep getting an error dialog which says "There was an error running the selected code generator: 'Length cannot be less than zero. (Parameter 'length')'". .

In the code generation log, it gives a stack trace:

Finding the generator 'identity'...  
Running the generator 'identity'...  
Length cannot be less than zero. (Parameter 'length')  
   at Microsoft.VisualStudio.Web.CodeGeneration.ActionInvoker.<BuildCommandLine>b__6_0()  
   at Microsoft.Extensions.CommandLineUtils.CommandLineApplication.Execute(String[] args)  
   at Microsoft.VisualStudio.Web.CodeGeneration.ActionInvoker.Execute(String[] args)  
   at Microsoft.VisualStudio.Web.CodeGeneration.CodeGenCommand.Execute(String[] args)  

I'm running version 6.0.7 for the CodeGeneration package.

So is this a bug with the CodeGeneration package? Is there something else I should probably look into for debugging this? How can I get more information for the cause of this error dialog?

Answer 1

I have the same situation. in asp.net 6 application
I used class program with Main in the program.cs file
"...
public class Program
{

[Obsolete]  
public static void Main()  //string[] args  
{  

.."

I have seen that in new projects the program.cs file does not contain the class program and the Main.
It may have some connection?

Answer 2

I have the same issue!

Answer 3

Hi, I have the exact same issue. It comes on Visual Studios for Mac... it works find when done from scratch in Visual Studio on windows even in .NET 6.

Anyone was able to find a solution?

Answer 4

After updating all nuget packages, errors were gone and was able to scaffold was able to generate all Identity files. Hope this helps.

Answer 5

same problem here

Building project ...  
Finding the generator 'identity'...  
Running the generator 'identity'...  
Length cannot be less than zero. (Parameter 'length')  
   at Microsoft.VisualStudio.Web.CodeGeneration.ActionInvoker.<BuildCommandLine>b__6_0()  
   at Microsoft.Extensions.CommandLineUtils.CommandLineApplication.Execute(String[] args)  
   at Microsoft.VisualStudio.Web.CodeGeneration.ActionInvoker.Execute(String[] args)  
   at Microsoft.VisualStudio.Web.CodeGeneration.CodeGenCommand.Execute(String[] args)  
RunTime 00:00:05.12  

dotnet list package
Project 'WebAuthentication' has the following package references
[net6.0]:
Top-level Package Requested Resolved

Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore 6.0.9 6.0.9
Microsoft.AspNetCore.Identity.EntityFrameworkCore 6.0.9 6.0.9
Microsoft.AspNetCore.Identity.UI 6.0.9 6.0.9
Microsoft.EntityFrameworkCore.Design 6.0.9 6.0.9
Microsoft.EntityFrameworkCore.SqlServer 6.0.9 6.0.9
Microsoft.EntityFrameworkCore.Tools 6.0.9 6.0.9
Microsoft.VisualStudio.Web.CodeGeneration.Design 6.0.10 6.0.10
Serilog.AspNetCore 6.0.1 6.0.1
Serilog.Settings.Configuration 3.4.0 3.4.0
Serilog.Sinks.Console 4.1.0 4.1.0
Serilog.Sinks.Debug 2.0.0 2.0.0
Serilog.Sinks.File 5.0.0 5.0.0

I already tried to scaffold with "-f" and "$env:codegen_trace=1", but I still get the same error without a hint. Plz help!