I transfered all sites from old server
Cpanel/WHM 56 with
Apache Version 2.4.23
PHP Version 5.6.26
MySQL Version 5.5.52-cll
to new server
cPanel Version 64.0 (build 14)
Apache Version 2.4.25
PHP Version 5.6.30
MySQL Version 5.6.35
Xoops sites are mostly 2.5.6 version
There weren't warnings in transfer process about those domains/sites but when I tried to open them on new server I got only blank page. I can't even open domainname/user.php
I tried to manually delete cache files but this didn't help.