internal error - server connection terminated

[clodhead]

Prestashop 1.5.3.1

PHP 5.4

 

I have a problem, when i try to change / view / modify category of product i obtain a general slowdown and further crash of the site.

In the frontend i receive this message: internal error - server connection terminated

Description: internal error - server connection terminated

 

The site remain down for about 30 minutes, after this time the site came online and the front end work fine.

 

I attach a log of error.

 

Any idea, thanks a lot.

 

error_log_prestashop.txt