Cannot create items in Google Calendar

If you use Google Calendar in Firefox, you might be unable to add calendar items. It displays this error: “Oops, we couldn’t create this event, please try again in a few minutes.”

A workaround was discovered by a user on the Google Calendar Help Forum.

harpseal said:

I think I found an answer. Delete the google calendar specific cookies and reload. After I did this it lets me create events. YAY! Hope this works for others.




Domains for cookies for


As part of my security measures, I don’t enable cookies by default for all sites. I enable them per-site, on an as-needed basis. So my whitelist is very large, but I think it helps more than it hinders.


So modern web applications depends on lots and lots of cookies. The applications depend on a large set of domains. Here is what I have learned so far: (my company's ADFS page)