IspConfig validates the admin user, but returns to login page

Hello Guys,

Another weird stuff happening in my Server, i woke up this morning and went to check on the server...aanndd...can´t login.
I type the user(admin), the password seems to be checked for an instant and it doesn´t seem to leave the login page, it doesn´t give an error message, nothing...at all.
Upon checking on the /var/log/ispconfig/auth.log i noticed that every time i tried to login, it was successful, there were plenty of entries like this one:
"Successful login for user 'admin' from x.x.x.x at 2016-12-27 18:45:33" <- this one is from the last time i tried to login.
cron.log doesn´t show anything useful
what could be happening?any suggestions?

 

Cookies? Cache?

Tried with a different browser that has no stored credentials or cache?

 

Hello M8,

Different browser, even from a cell phone and the result is the same...i´m clueless

 

Solved, but i´m still clueless about what happened since the logs would not catch errors.
What i did was the most dumb action possible(*ndows solution), i rebooted the server about 4 times and it worked again.

 

still weird though.