o..o

Hi, I just installed fresh Prestahsop 1.7.2 and I'm getting error 500 when trying to access /admin. Frontent seems to be working ok. Server log shows nothing. Even when I set: define('_PS_MODE_DEV_', true); I'm still getting: 500 Application errorThe server encountered an internal error and was unable to complete your request. This may be caused by application error or request timeout. If this error is permanent, please contact webmaster. What could be the problem? Thanks