Hi, I had that error message for two days, most of the time opening Gmail ended with crash and sending crash report. Before that I had to click OK like 6 times in this urlDomain.empty() pop-up window.
Reinstall was not fixing the error so I've downloaded beta and tried with turning off the AdBlock and Proxy as someone said. That worked, I've turned it back on and it's still working so... I still have no idea what actually fixed that bug.
BTW it happend to me for the second time.