Layerslider Problems with purchase code

Hi,

first of all it is not possible to update the layerslider from the backend.
the purchase code i got does not work with layerslider, there is an error: You need to authorize this site in order to get upgrades or support for this plugin

but the main problem is, that i had internal server errors a few times
after i installed the template everything worked fine, i just installed the refered plugins for the game addict template – no more.

i released the internal server error after deactivating all plugins across ftp, then i activated them in the backend and the site worked fine…then from one minute to another the internal server error occured without any changes..

so i think there is a problem with the layerslider,
what can i do do fix this

kind regards,
robert