Hello nmama,
Thanks for reaching out to us!
Can you send me a link to “page 11 of our website and tech tools manual”?
To make sure I’m understanding you, when following the Testing for Conflicts procedures you were able to fix the problem of the “Invalid user_key” error? The remaining error is a broken URL to the event?
Try re-enabling all the plugins excluding the one that you initially believed was causing the conflict. After all other plugins are activated, try going to “Settings” -> “Permalinks” and re-saving your permalink settings. Let me know if this helps with the current issue.
Thanks!