Problems with Global Gallery

In global gallery, below the manage images button it has the following error message.

Fatal error: Allowed memory size of 136314880 bytes exhausted (tried to allocate 78 bytes) in /home/linksssp/public_html/wp-includes/cache.php on line 569

When I go to upload some images that are low in resolution, and small in size they upload, but it wont let me ‘Insert Gallery’.

I’m assuming it will not let me due to the error stated above, but what is the error and how can I rectify it?

Hope someone can help!