My customers were not able to login in front end . However i did have access to admin panel. I tried every single trick and tip available . nothing worked .
I had an old backup of “app” and “ “downloader” folder.
First i made copy of current folders , then i replaced these two folders with my old backup folders which i had.
During this process , i set 503 Service unavailable for front end .
If you don’t know how to do 503 , simply rename your index.php for few minutes .
make sure you either delete or rename already existing “app” and “downloader” folders.
once you have finished replacing , Don’t forget to clear files in var/cache and var/session .
and in the end correct your file name for index.php(Only if you changed it).
It worked for me .
I spent two days , couldn’t find any other way of solving this issue . I contacted my hosting provider for support , although they are nice people but They were horrible in their tech support,