{HELP}-update

[karen11]

displays an error when updating

 

prestashop1.4.9->prestashop1.5.2

[Ajax / Server Error] textStatus: "error" errorThrown:"Bad Gateway" jqXHR: " Service Temporarily Unavailable

 

The server closed the connection without sending any data.

The server is temporarily unable to service your request due to maintenance downtime or capacity problems.

Due to heavy load on the server, connections may be temporarily blocked from locations that fetch an unusually high number of pages.

We apologize for the inconvenience.

 

info:

Version Prestashop: 1.4.9.0
Server information: Linux # 1 SMP Thu Dec 6 07:12:24 EST 2012 x86_64
Version of the software on the server: Apache
Version of PHP: 5.4.10
Version of MySQL: 5.1.66
Information about the shop

 

 

please help