When registering for an event.
Previously working now returns a screen without the template and just the message with the name of the event registered for.
Try registering again and says I've already registered, but does not show in My Events or in the back end records.
I cannot figure out what to do. I have uninstalled and reinstalled DT Register
Doubt it's a bug with duplicate registration prevention. Tons of people use that and you wouldn't be the only one having the problem if there was an actual bug. Probably some type of issue/conflict specific to your site. You should submit a support ticket so we can check it out.