could not throw away exiting file/folder at destination

Hi,
I have a rule that I use all the time (for years) - moving specific pdf's to specific dropbox folders . When the pdf's get updated in their monitored folder they move and replace the previous files in dropbox. Without changing anything in the rule I suddenly I get a notification "could not throw away exiting file/folder at destination".
It may be a permission issue. I tried to fix/re-apply permissions the destination folder with no success. Does anyone know how to tackle this issue?
Many thanks
Ofir

Solution found! I reinstalled dropbox app for Mac and everything is back to normal.

Sorry for the self-replies
The issue is back again.
So If someone knows please assist me.
It appears to me as a permission issue that could be unrelated to directrly hazel.
Ofir.

Try the troubleshooting guide here: https://www.noodlesoft.com/kb/hazel-tro ... ing-guide/