NoMethodError when trying to accept an invite

Tried to accept an invite to join a campaign, got this error message. Same error through the notification system in the top right corner and via email.

I'm sorry you're having trouble with the site. Can you please follow Steps 1-3, taking special care to temporarily disable all browser add-ons and extensions, temporarily pause your anti-virus, and try switching browsers (for Chrome/Firefox specific issues) to see if one of those components is causing the problem. If all of that fails, please follow Step 4 , including providing all of the necessary information, so that we can further assist you.