I noticed some error messages from !Swatter in my chat pane. Nothing in nUI6 appears to be broken, borked, funky or any other nice descriptive wording I do have !Swatter setup to grab taint errors as well as reg errors, but I believe these were all merely taint in combat. I'm attaching them to this post just in case you want to see them.
Great work on nUI6 so far though. Can't wait to see the customization and other options we may have coming.