Error When Adding Website

Everytime we try to install the plugin, it installs successfully but then it does not activate. Instead the whole website goes down and we get the following error:

Fatal error: Allowed memory size of 62914560 bytes exhausted (tried to allocate 364593 bytes) in /homepages/17/d506501721/htdocs/clickandbuilds/EZDoctors/wp-includes/wp-db.php on line 3020