I was having issues with adding activity until today's patch, now i've had a few work but a few have received this error "java.lang.UnsupportedOperationException: notifySubscriberCountChange is not implemented for contacts API" - it's possible I've made a mistake, but the error doesn't look like one I'd get if it was on my end, and a few have worked.
Thanks for posting. What you are experiencing does look like a bug on our end. Would you PM the details of the call so we can verify what is going on?
Wanted to give a quick update here. Looks like this is an issue with using bulk imports only with our new Contact Management System that we're moving our customers over and is really a false alarm (the imports actually succeed). We're working on fixing this up and hope to have this cleared up soon so that we can get back to giving you accurate errors in the bulk imports. Don't have an expected date yet for this fix but will update once we get one.