Hello how to solve this issue after try install the new custom theme paid on marketplace ?

Hi. It may be incompatible with version 4.6 Have you tried contacting the author about your problem?

Have you checked to see if you have anything showing in your system logs? You can find these in Support, in the top right of your admin CP

Solved:

My problem is memory limit.

I set up memory limit to 256 and the problem is solved !

Glad to hear thats sorted 🙂