Hi Richelle,
Sorry for the troubles with updating! The move from 3.12 to 4.0 was a big one so there are definitely some things to watch for that might cause this sort of thing.
First off, do you have a folder in your theme directory called tribe-events? If so, please remove it (back it up on your desktop or somewhere else, of course). That will make sure no prior customizations to templates are conflicting with the latest versions.
Next, are there any calendar-related snippets in your theme’s functions.php file? You can check this by searching for anything with the word “tribe” in it.
Lastly, please try a manual update. In other words, deactivate the old versions, delete them from the server, download the new versions, and install them. I would suggest installing and activating the new plugins one at a time instead of in bulk. Here are more specific step-by-step instructions for manual updates.
Let’s start here and see what we find.
Thanks!
Geoff