I've been performing some house cleaning on my site by removing unneeded modules. I was suffering from the "user warning: Got a packet bigger than 'max_allowed_packet' bytes query: UPDATE cache_update SET data" error prior to cleaning house.
I removed several modules and it addressed the "error message" but upon install and enabling of the email verification module the error came back again.
I am not sure if it is module specific or because I have too many modules, I have been running >50 modules without issue/error messages up until I started cleaning house. When I installed this module, I had figured I had removed enough modules to alleviate any server drain, but was surprised that enabling one module brought the error back again.
The error is in a red box and is extremely long. It could be be related to "cache_update".