Can Not Access Back Office ''themes'' Menu

[Seirios]

Hello,

 

I use Prestashop 1.5.4.1

Every time i try to access back office ''Themes'' menu after 300 seconds i get an error 500.

My server's error logs are showing  the following :

 

Error 500 12:30:03 pm

 

GET /admin/index.php?controller=AdminThemes&token=0d9f9a011be5fab0348655311d1f9fce HTTP/1.1

 

 

Warning - 12:30:03 pm

 

mod_fcgid: read data timeout in 300 seconds, referer: https://store.com/admin/

 

 

Error - 12:30:03 pm

 

Premature end of script headers: index.php, referer: https://store.com/admin/

 

 

Thanks