Error when adding myself to a meetup

Can anyone help me with this problem: Mannheim Mini-Meetup 01.05.24 - #18 by smiling_star

I try to add myself to a meetup but it doesn’t work. I also refreshed, logged out and in again, used different devices.

@Bille asked my to post this here. It seems she had the same problem when she tried to add herself so it might be a general problem.

Thanks a lot!

Edit: Here’s the screenshot of the error that’s always shown when I try it:

It also gives me an error (500)!

Hope someone can shed some light on this.

Security updates were made today. Maybe it’s related to that?