Impossible to add or select images

I am working with Joomla 2.5.8 and Hikashop Business 2.2.1
Since one week it is impossible to add or to select any image.
The error code I have is:
Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 27068692 bytes) ..../administrator/components/com_hikashop/helpers/image.php on line 762

I have no image in my product and the image I was trying to upload is only 310 kb.

I have to find a solution for that!
Thank you.

Hi,

Have you changed anything on your website, or server configuration recently ?
Thanks to give us the corresponding line in the file "..../administrator/components/com_hikashop/helpers/image.php "