Messaggio originale di EmperorFaiz.docx:

...thank you. What bullsh*t bug. I hope the devs fix this soon.

That wasn't even the correct solution

It's not a bug, but it is something that probably should be addressed. You know the messages Blender Source Tools gives saying something like "SMD only supports 128 bones"? Well, at some point (I don't know when) there was an update that allowed SMDs and Garry's Mod to support around twice as many bones. It may not be important, but this warning message should be updated accordingly in future versions.

Messaggio originale di SuperMario20:

I have just experienced this issue and I believe I know what is causing it! Check your files in your project under "Source Engine Exportables". Make sure there are no duplicate names. What seems to be causing this is having a collection named "ExampleName" and an individual mesh named "ExampleName" that is not a part of a collection. (ExampleName is a placeholder name) This will make Blender Source Tools read them as the same thing when exporting and causes it to freeze because it can't distinguish them. Make sure to rename either the collection or individual file prior to exporting to fix this.

You were close, but it ends up being the name of the skeleton that causes the problem. If a skeleton has the same name as one of the collections then Blender freezes. It's still strange that this only recently started being a problem.

Will this do?
https://drive.google.com/file/d/1a7vb-WEFV0hPFsbM0qk7rCCW0t8_aU_b/view?usp=sharing

A strange and irritating thing that started happening just a few days. While using BST version 3.2.5, Blender 3.3 and 3.4 will freeze immediately when I click the "export" button. It doesn't even load the popup list of exportable files to pick from.

The strange part is that the freeze only happens if an object is selected or highlighted when there is more than one skeleton animation in the project. If I select and delete an object so that no objects are highlighted, Blender doesn't freeze and the popup with "Scene export" appears as it normally would. I checked with Blender 2.9 and lower and they don't have this freezing problem.

This never happened until only a few days ago, as BST could export multiple animations in Blender 3.3 just fine before. It could be related to a recent Windows 10 update, but I don't really know.