Hi magnetar,
we are really sorry for the issues you are facing. Indeed it looks like a weird issue!!
As you point out several scenarios, let me go through them:
Last night I noticed one event was not pulling across from Teamup.
Maybe the event had the same UID identifier as any previous version. How is this import? Is this an automatic import using a cronjob and importing from URL?
I tried deleting the calendar and category and starting afresh, however, this is where more problems emerged. The calendars in 'Manage calendars' would sometimes be displayed in the backend and sometimes there would be no calendars.
That's weird, but probably related with the categories removal you did. Did you actually sent JEvents Categories to the trash and then empty the categories trash? Also, can you think of a pattern for when calendars were showing and not?
I decided it might be best to uninstall JEvents and start from scratch. However, uninstalling is not a complete uninstall. It still remembers the past events, calendars, categories etc.
Historically we have neverd performed a full uninstall as to avoid data loss when uninstalling by mistake...
So if you want a fully uninstall with data removal follow these steps:
1. Uninstall JEvents
2. Use PHPMyAdmin or similar and remove these tables from your DB:
#__jevents_catmap
#__jevents_exception
#__jevents_filtermap
#__jevents_icsfile
#__jevents_repetition
#__jevents_rrule
#__jevents_translation
#__jevents_vevdetail
#__jevents_vevent
#__jev_defaults
#__jev_users
That will fully uninstall JEvents (unless you had other JEvents Club Addons installed in which case you need to take care of them)
My advice is to perform a fully uninstall cleaning your database too and then install the component and add the calendars again. That should work with no issues.
Also if you experience again the missing event thing, please contact us and we will check into it
Best!!