I've been hosting quite a few webinars lately via the GTW integration with Marketo. By and large, it's pretty sick... It just works. However, in the last 2 webinars I've set up, I've had a couple instances where a random user gets a "registration error" when I change their status from "invited" to "registered" (we're partnering with a 3rd party subject matter expert for the content, so we have to import registration lists and set the status).
Does anyone have any ideas why this might be happening? Looking at the lists, there's nothing particularly special about these users... Email addresses and all other imported data looks fine, they're not blacklisted... Activity log just craps the bed when it gets to step 2 in our status progression.