Check the permissions in your Zotero data directory. Generally that would result in a different error, but if you're saying you copied the data directory from another computer and this started happening, that's the most likely problem.
Also, do you have your data directory in the default location, or somewhere else?
If you go to your Zotero data directory, is the 'storage' folder a regular folder?
Report ID: D2100034147
When I drag several items to "my library", the items cannot be added into the library, and Zotero has no reactions.
Steps to reproduce:
1. Start Zotero.
2. Drag item(s) to the folder in "my library"
Also, do you have your data directory in the default location, or somewhere else?
Yes, I have my data directory in the default location. I didn't change anything.
If you just try to drag a PDF from your desktop, does this happen?
It doesn’t look like there’s actually any problem with file syncing, so this may just be a problem with what you’re trying to drag.