I’ve been having issues with my Gmail while using the newest developer builds of Chrome. When clicking on an email message the loading display at the top of the screen would come on and it would just sit there for approximately 30 seconds before displaying an error message and then allowing normal use of email. I thought it may have been due to the dev build but it works fine running dev on my home machine.
Thankfully this one had a very simple solution. Click the wrench (settings) button. Go to Options. Personal Stuff, Clear Browsing Data… I only checked Clear Cache and set the Period to be ‘Everything’ and Gmail started working normal again.