Deactivated collections are deleted when the file is reopened

Hello,

We are a company specialized in architectural visualization and have been working with Blender since 2015.

These days one of my employees had several times the same problem. A deactivated collection was deleted when closing and reopening the file. We are working on version 2.93.4.

It’s not practical, because if you’re not careful, you don’t realise that part of the project is missing.

Does anyone have any ideas? I’m not sure where to look? Is there perhaps a shortcut or a function that has been activated unintentionally?

Thank you in advance for your help.

Good day and best regards,

Nathan

Here is a file containing the bug. If you create a new collection and save, the new collection will be deleted…

https://visualizations.ch/download/Blender_file_with_bug.blend

If you put Blender with the default settings (load factory settings) the bug is no longer present. Thanks to this, we could identify the addon that was causing the problem: “Graswald Pro 1.3.4 - Team”.

I also tried to load factory settings and to install only the Grasswald addon. Then when you open the file with the bug (previous post), when you create a new collection, it will be deleted when saving.