If you can't join a group because the procedure doesn't go through or because you're getting blocked by an error message, there may be several reasons to explain this behaviour:
The organizer of the group you're trying to join has set up questions to accept new members. Organizers can regulate who joins a group by listing a set of questions for new joiners to answer in order to be admitted to the group. If this is the case, ensure that you answer all questions for the organizer to thoroughly examine your application.
You were banned from the group you're trying to join. Organizers have the option to ban some members for various reasons. Once a member is banned, they cannot rejoin the group from which they were banned.
Browser extensions might be blocking the join process. Some browser extensions — especially ad-blocking, privacy, or tracking-prevention tools — can interfere with the connection to Meetup and prevent the join request from going through. These extensions may block or modify parts of the page that are necessary to complete the action. If you're joining from a web browser, try disabling these extensions (or pausing them for meetup.com) and then try again.
The main organizer closed the group you're trying to join. If you're getting a generic error stating that the group you're looking for cannot be found, it's possible that it was shut down by its main organizer in the meantime. Another possibility is that the main organizer stepped down and no one stepped up to take the lead of the group in their place. In such cases, groups typically undergo a 30-day grace period before they get permanently closed.
A temporary bug is affecting your experience. If none of the points above explain your case, try changing the device you're accessing Meetup from. If the issue occurs on mobile, try accessing Meetup and joining your group on desktop, and vice versa. Sometimes, changing platforms makes a difference!
The Meetup app needs to be uninstalled and reinstalled on your mobile device. If you're experiencing this issue only on Meetup's mobile app, try uninstalling and reinstalling it on your device, ensuring you download the latest version of the app. Here are the relevant steps for both iOS and Android devices.