This issues occurred after my server crashes(both system board and hard disk) and when I transferred backed up copy to another server. I made sure database is transfferred correctly and typed in the correct user id and password. But I just can not login. It says “Your PHP sessions don’t seem to be working”. But actually it is, after I log into Mambo, all well. Sessions transferred data cortrectly including user id.
Finally I figured out it is caused by permission error. The application can not write cached data to some directory! After chown to ap..e:ap..e all works great.
BTW, config.php is missing from backup because it my be prev. owned by root and is not able to back up.
The symbolic link is not backed up for sure.
The whole disaster recovery is time consuming and I bet I lost something I can never recover!
Same happens if no more disk space.