This issue and issues like App Error: AbanteCart core v.1.2 Resize image error related to the limited memory set on your server or host. The standard PHP memory requirements for AbanteCart are a bare minimum.
Try to increase the memory to 128M or more.
If you have access to the server's php.ini please edit the memory_limit parameter.
memory_limit = 128M ;
If there is no section already for this, place the above line at the end of the file. In case PHP is running as an Apache module you may try to edit .htaccess file
php_value memory_limit 64M
This will not be possible in some shared hosting environments, though your host may be able to adjust it for you.