How to Restore Deleted Folder
I accidentally hit the DEL key while the pointer was at a folder. The folder automatically was deleted without prompting me. I have tried to undo CTRL-Z, but nothing happened. I checked the Trashcan, but it was empty. Any option to restore a deleted folder? Thanks!
Anyhow, if you just did this, you should be able to restore a deleted collection from one of the automatic backups. Note the specific instructions for restoring collections.
Also note that the items are most likely still in your library root, even though you deleted the collection.
A future version of Zotero will make it possible to restore a deleted collection from the trash.
https://github.com/zotero/zotero/blob/48c7c60bf1ef4c0355f6b27cd2247db0accaf9b2/chrome/content/zotero/zoteroPane.js#L2283C7-L2355
It can't delete a collection without prompting. You can try it yourself right now with a temporary collection, so I'm not sure why you're arguing about this.
I linked to exact instructions for restoring a deleted collection above, so I'm not sure why you're following unofficial instructions from some other thread. If you're going to post here, please trust that we know what we're talking about and are going to give you correct advice, or else don't waste our time.