I'm trying to debug my azure functions (Python) in VS Code for macOS. Everything was working fine until last week when I started getting this error when trying to debug using 'Attach to Python functions'

Reverting my code to older commits (where it was definitively working) did not help. I also re-installed VS Code, still getting the error.

Building into a docker container and running the container works, it's just the debugging in VS Code that does not work.

[2025-03-31T09:40:13.208Z] A host error has occurred during startup operation 'fea6e68a-2e7f-43ca-b8e4-3e32814d60fa'.
[2025-03-31T09:40:13.208Z] System.Private.CoreLib: Exception has been thrown by the target of an invocation. Could not load file or assembly 'System.Memory.Data, Version=6.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot find the file specified.
[2025-03-31T09:40:13.208Z] .
Value cannot be null. (Parameter 'provider')
[2025-03-31T09:40:13.233Z] Host startup operation has been canceled

I'd be grateful for any hints on how to fix this

I'm trying to debug my azure functions (Python) in VS Code for macOS. Everything was working fine until last week when I started getting this error when trying to debug using 'Attach to Python functions'

Reverting my code to older commits (where it was definitively working) did not help. I also re-installed VS Code, still getting the error.

Building into a docker container and running the container works, it's just the debugging in VS Code that does not work.

[2025-03-31T09:40:13.208Z] A host error has occurred during startup operation 'fea6e68a-2e7f-43ca-b8e4-3e32814d60fa'.
[2025-03-31T09:40:13.208Z] System.Private.CoreLib: Exception has been thrown by the target of an invocation. Could not load file or assembly 'System.Memory.Data, Version=6.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot find the file specified.
[2025-03-31T09:40:13.208Z] .
Value cannot be null. (Parameter 'provider')
[2025-03-31T09:40:13.233Z] Host startup operation has been canceled

I'd be grateful for any hints on how to fix this

• function
• visual-studio-code
• debugging
• azure-functions

1 Answer 1

We also just started seeing this today running C# Azure Function Apps in .NET 6. Are you using NServiceBus also?