I did not notice that my WassUP was not gathering data for a little while, which has been a bit of a pain to be honest. The fix is simple.

1. Locate and edit your wp-config.php (I did it in Transmit FTP Client)
2. add this line to it:

   define( 'WP_MEMORY_LIMIT', '96M' );

3. save/upload this edited document back in place
4. disable and re-enable the WassUP plug.
5. Profit.