CreateRuntime crashes after workflow restart when ExpressionTransform is used with a Dynamic Class

[rachelmcassidy]

I recently implemented python scripting into my workflows, and I've come across an incompatibility with the ExpressionTransform operator. I've attached a simple workflow that will hopefully be able to recreate the following issue:

• When ExpressionTransform is used to create a Dynamic Class, the python runtime will crash on the second attempt to run the workflow with the error "Exception has been thrown by the target of an invocation." It will run again if I restart the editor or click "Reload extensions".

• If ExpressionTransform runs some other operation like Convert.ToDouble(it), the workflow and python scripts will run normally for as many times as the workflow is restarted.

Potentially relevant context:

• I recently updated all bonsai packages to their latest versions.
• Python version: 3.12.7
• The output of ExpressionTransform dynamic classes no longer shows as DynamicClassX, but rather <>f_AnonymousTypeX<>, but still works with the correct fields.

Is there another way to set up the python runtime to avoid this issue, or should I remove all dynamic classes from my workflow? Thanks for any suggestions you can provide.

python_scripting_crash_test.zip

[glopesdev]

@rachelmcassidy does this still happen if you revert expression scripting to an older version (you can select it from the package manager)? That would be an interesting test to understand if the regression is related to some of the changes we introduced more recently in the library.

[rachelmcassidy]

@glopesdev I get an error about accessing the .dll when I try to revert the expression scripting package, even when I run the Bonsai editor as an administrator

[glopesdev]

@rachelmcassidy do you have more than one bonsai open? The way this could work is if you have one bonsai with the original workflow loaded while trying to remove a package: since the workflow is using it the file cannot be deleted.

[rachelmcassidy]

@glopesdev I did have several instances running. Thanks, that fixed the package updating.

When Scripting.Expressions version is reverted to 2.9.0, the runtime/DynamicClass crash issue is resolved.