Perhaps remove the linked calendar, or linked address book.

I don't use Google for address book or calendar or anything else for that matter. This has only just started. If I do anything in TBird this damned pop-up appears. I always hit Deny and then a minute later it re-appears. This is precisely why I don't use Google. It's so intrusive.

I don't use Google for address book or calendar or anything else for that matter. This has only just started. If I do anything in TBird this damned pop-up appears. I always hit Deny and then a minute later it re-appears. This is precisely why I don't use Google. It's so intrusive.

Clearly you do use something, or tried to set it up and failed. It would not appear, unless there was something linked.

Perhaps post a screen shot of what the page looks like. That might offer something of a clue.

Also; Could you please do the following?

1. Open the menu > Help > Troubleshooting Information, then click Copy text to Clipboard.
2. Go to https://pastebin.mozilla.org/, paste the clipboard by right clicking in the large text area, select paste from the menu, change the retention period to expire in 28 days, use the Paste Snippet button to create a page containing your info, then copy the resulting URL (address) of the page created.
3. Open a reply to this post, and paste the URL to your troubleshooting information you just copied.
4. Please also provide results for the following test on your system

Does Thunderbird work as expected in Thunderbird troubleshooting mode?