OpenCart CMS致命错误：允许的内存大小为536870912字节耗尽

I have made a story website with OpenCart CMS, after 3 month it gives this error:

Fatal error: Allowed memory size of 536870912 bytes exhausted (tried to allocate 12723 bytes) in /home/pasarg24/public_html/vqmod/vqcache/vq2-system_library_url.php on line 30 

my domain name is www.pasargadfarsh.ir