Cannot Access Joomla Admin After Uninstall

[haserb]

I downloaded the beta version (3.9) as well as the latest version of Jdownloads (3.265). I inadvertently installed the 3.9 version and after realizing this mistake uninstalled it. When I attempted to upload and install the latest version of Jdownloads (3.265), I received a post installation error message: 1054 Unknown column 'file_id' in 'field list'. I cannot access the Joomla frontend nor Admin areas of my site. The joomla installation is 3.9.13.
What measures can I take to repair this?

[ColinM]

Hi
hmm!  do you have a backup? will resarch
ColinM

[Arno]

Hi haserb,
it was not a good idea to upgrade (inadvertently) to the new version and try then to go back in this way.
1. you get viewed a special message which warn you when you start the upgrade process
2. we have never tested to deinstall the new version 3.9 and install then again the old version.
3. the upgrade process change some database data so it is not more compatible to older versions