Your plugin suddenly stopped working and will not reconnect

This was previously working, but then started giving the message “Please try again after re-connect your account.” and import failed. I went to your Settings tab and cleared the old authorization. The OAuth Key and OAuth Secret were already correctly filled in. I clicked Meetup Authorization: Connect, and this took me to a page on secure.meetup.com that displays the following message:

Invalid Authorization request
If you were directed here by another application, contact its developer

So I am contacting the developer, as instructed.