Error occurred: 500 - internal server error

Hello.

I getting the Error occurred: 500 - internal server error when try to include the plugin folder in the snaphot.
with other folders en database no problem.
I increased the memory to 512 end try to switch form pclzip to zip. stil the problem
An when i using the zip option i van restore the database, getting the erro he cant find the table. So o have to stay to the pclzip option.

Any idea what to doe?
thanks
torsten