Webmail Internal Error 500

[valy]

When I try to acces roundcube I get Internal Error 500
How I do locate the problem? Where is webmail logs?
VestaCP running ok but when I enter on /webmail I'm getting error 500

[lotnomore]

When I try to acces roundcube I get Internal Error 500
How I do locate the problem? Where is webmail logs?
VestaCP running ok but when I enter on /webmail I'm getting error 500

Have you tried to reinstall? I dot not mean fresh install again.