引用自 Léa ♥：

I just noticed that all my addons were deleted from the workshop folder and some were set to read-only.

Loading L4D2 tools mode, and loading L4D2 from Hammer after a map compile are both different from loading L4D2 normally.

Specifically they don’t have a workshop file. So anytime you load L4D2 in tools mode or from Hammer, the workshop file goes away. Then when you go and load L4D2 normally it will (usually but not always) have to re-download all your workshop files again.

This is somewhat useful because you don’t have to worry about getting error messages or conflicts from workshop files (including your own files which may be on the workshop) while working on your own projects. But it means you need to plan ahead for when you actually want to play L4D2 normally.

You can move files (make sure they are fully downloaded first by starting L4D2) from the /addons/workshop/ file to the /addons/ file to keep them on your machine. But then you need to unsubscribe from those files and they won’t auto update.

As for your tools mode not working, I’d suggest verifying the cashe files for the authoring tools and L4D2. Normally tools mode starts up with just menus visible (upper left corner), and a viewport (upper right corner). Then you need to use the menu to open something or us F10 to switch to (or back from) seeing the game mode window. But in that clip all things look right, except the menus and text labels are missing. So that might be a corrupt file issue.

Thanks for your advice. I fixed the files and restarted 'tools' but the first time, it shut down on launch. The second time, it crashed on loading and the 3rd time, same as the capture...
Maybe there are logs to explain the game crash.