Hi Vicki,
I’m sorry that you’re running into this issue, but I’ll be happy to help you figure out what’s going on.
Do you have any customizations currently on your site? The “tribe_custom_venue_validation” function is not one of our defaults, but I did find it in this support thread. As this post was from 2016, it’s definitely possible that this is no longer compatible with the current versions. Can you try removing this and see if that gets rid of the error?
If you were using this to set required fields, then I would recommend taking a look at this (more recent) article, which has some code that you can use to change which of the Community Events fields are required.
Please let me know if this gets rid of the error (and gets things working the way you need)!
Thanks,
Jennifer