Calling external .dll fails after upgrading to .NET 8

[Schoof-T]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

I have a .dll file from a company that I need to call to process some work. The dll is created in powerbuilder.

The .dll required the application to be x86, required Winforms and a bunch of powerbuilder dlls.
I created an API as a wrapper around this .dll, I simply referenced the .dll file

and called it's methods:

 var generators = new Abs_Pdf();

 if (model.PageSize.HasValue && model.Orientation.HasValue)
 {
     generators.set_pdf_size(model.PageSize.Value, model.Orientation.Value);
 }

 _logger.LogInformation("Start Converting Template To Pdf - {table}:{id}", model.TablePrefix, model.PrimaryKey);

 var result = generators.get_template_pdf_file(model.TablePrefix, model.PrimaryKey, ref outputPath);

This all worked until I wanted to upgrade my API to .NET 8. Now calling the dll gives an exception (the exception is caught in the dll I assume, because it's simply returning a string saying "Failed!".

Are there any changes to calling a referenced library?

I also contacted the company and asked them, but seeing as it worked in .NET 7, I thought maybe it should/could work in .NET 8 as well.

Expected Behavior

Calling the .dll library would not result in an error.

Steps To Reproduce

I cannot share the .dll as it is intellectual property.

• Create new .NET 7 API project
• Add external library (dll)
• Call external library --> Success
• Upgrade to .NET 8
• Call external library --> Fail

Exceptions (if any)

No response

.NET Version

8.0.100

Anything else?

No response

[martincostello]

Could you please provide the specifics about the exception that occurs when you try to call the library? You should be able to configure Visual Studio to break when the exception is thrown, even if it's caught in the other library, to see what happened and what the stack trace is.

Hi @Schoof-T. We have added the "Needs: Author Feedback" label to this issue, which indicates that we have an open question for you before we can take further action. This issue will be closed automatically in 7 days if we do not hear back from you by then - please feel free to re-open it if you come back to this issue after that time.

[Schoof-T]

Could you please provide the specifics about the exception that occurs when you try to call the library? You should be able to configure Visual Studio to break when the exception is thrown, even if it's caught in the other library, to see what happened and what the stack trace is.

Thank you, the excpeption I receive is the following:
'Could not load type 'System.Drawing.Printing.PrintingPermission' from assembly 'System.Drawing, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'.'

[martincostello]

Looking at the code in dotnet/runtime, the System.Drawing.Printing.PrintingPermission type was moved from the System.Drawing assembly to the System.Security.Permissions assembly (code around .NET 8 preview 4 (dotnet/runtime@c0cca33#diff-7b9021540cd5d7eb20f120d664bf21947770715ddbfaf2cf5490501ec7699a70).

Is System.Security.Permissions published/available somewhere to your app?

Seems like the refactoring is breaking something compiled against an older version that now can't find whatever it is it's looking for, which appears to be related to Code Access Security, which isn't really a thing anymore in .NET (Core).

[Schoof-T]

Is System.Security.Permissions published/available somewhere to your app?

I could just manually reference maybe? Is the System.Security.Permissions available somewhere secure?

[Schoof-T]

I tried adding the nuget 'System.Security.Permissions' but nothing changed. Any further ideas?