Well... I just had THIS SAME EXACT ISSUE...
Login with correct data, gone back to Login page, NO ERROR or anything.
I tried all solutions here, nothing worked (clear cache, browser cookies)
I had 2 installs (one the first test, the second where i started to do the site as it should)
Site 1, HAD THE PROBLEM.
Site 2, working normally...
Same Server, same php.ini, same .htaccess ... very similar installs, just a few pages on each one, not live, etc.
For me was easy to think ... to isolate things...
but I still dont know what exactly got fixed and HOW... maybe some experienced used will know.
I copied the /CORE/CONFIG/CONFIG.INC.PHP from the WORKING SITE to the NON WORKING SITE...
So I tried to login from the NON WORKING DOMAIN/MANAGER ... using the WORKING domain database/data....
and it worked! ... so no problem on files, directory permissions, etc.
Then... for MY SURPRISE... when I put the correct paths, and database data to the config file... IT WORKED!
I also changed on the mysql config... from database sessions, to "" so it use normal sessions.
I’m not sure what of this make it work...
but if anyone have an idea or can reproduce this error... It would be good to:
1) Document this (looks like a bug for me) as well as the solution.
2) Fix for next release
So if there’s anyone there with this problem, or if you can reproduce it:
First try to change in table modx_system_settings, the value session_handler_class to ’’ (nothing), you can easy do this with phpmyadmin.
then try to login again.
If this dont works, you can always have another install, and copy the /CORE/CONFIG/CONFIG.INC.PHP.
this should work in some or another way...
if anyone knows how exactly does this works and why happends, please advice.
Regards.