I recently removed JDownloads in totaly, first from Joomla, then the remaining items in the database (phpmyadmin).
After that I did a whole new JDownloads installation from within Joomla. I created a folder via FTP, in my case this is the folder "dbcom-data" and it is outside the Joomla environment "/home/public/sites/dbcom-data".
Also change the path settings: Upload directory path * /home/public/sites/dbcom-data
In the path settings there are two left, which are set as shown below:
Preview files directory name * _preview_files
Temporary directory name * _tempzipfiles
Maybe I am forgetting something?
All information is more than welcome so that I can import my old layouts again (xml files).