thanks for the report. Please let me know the 'blah blah' part as well, as this is rather relevant (also the 'nil' you're reporting is somewhat confusing). Right now I've added a ton of checks and need to know which to keep and which I can remove again to reduce cpu usage.
Basically these tests arent necessarily errors, we'll have to deal with the fact that not all roster information is availble to the client at all times. Once I know exactly in which situations which error occurs, I will simply hide the errors and reschedule a roster update in such cases.
Oh, a not to everyone: if you have access to the test realm, please also post if the problem occured there or on the live servers. Blizzard fixed an event related bug on the 1.11 servers as I was told yesterday, so this needs some testing.
i've been mostly using it on test. It was a count mismatch, and looked like the one in the screenshot above, except the first count was nil, and the second one was a number in the 30's. I'll try to get a screenshot the next time I'm it happens.