phpmyadmin 500 internal server, mcrypt not found

Hi, Trying to install phpmyadmin. regardless of the php version I choose for the virtual server it always gives a phpXX-mcrypt cannot be found, visiting the domain/phpmyadmin gives 500 internal server.

There is an encrypt installed, 5.4 I think? I tried the more repo and installed more-php56-mycypt-php and I did not get any 'not found' message on install oif phpmyadmin but still 500 internal server. So removed said repo and mcrypt

The webmin is version 1.791, don't know about the virtualmin as I cant find anywhere it says what version. recent install and constantly updated so whithout a way to see not sure how to tell.

Any help would be great

Regards BaD