When you cannot connect to jenkins.io/hangout with your Gmail account... On the same day, are you able to start or connect to a new Google hangout URL via these steps?
1. Switch to your Gmail account
2. Go to https://hangouts.google.com/call/
3. Click "Copy Link to Share"
4. Share the new link, e.g. https://hangouts.google.com/call/PkmbvkuZ5HbXDWy5X2v_AEEE
I have a hypothesis that there were system-wide issues connecting Gmail and Google Hangout reliably in November, instead of an issue specific to jenkins.io/hangout only.
On the same day (November 29th) when Oleg Nenashev created this bug report, I see a person unrelated to the Jenkins community reported following bug report, "not been able to use hangouts on my gmail accounts for hours" to Google:
Hi, i've not been able to use hangouts on my gmail accounts for hours.
by Rebecca Maxon Nov 29
Hello please i cant use hangouts on my gmail account, it keeps showing something's not right,
We're having trouble connecting to Google. We'll keep trying, Please kindly resolve this problem, thank you
After skimming the Google Hangouts Help Forum, I see many reports of connection issues throughout November