When I was testing Collector I made a test feature but got a message that the update failed-updates could not be sent and I can cancel or retry. Cancel abandons the feature and retry returns the same result.
This did solve our issue that we were having with this exact error. I am going to do more investigations as to why SQL is having a memory pressure problem and what exactly that means in regards to use of spatial types on SQL Server.
I believe the underlying cause of "There are no rows in the current fetch buffer" error is archiving. I was getting this error a lot and had to disable archiving to stop it. Luckily i was just trialing offline and dont have a major need for it at the moment.
Would be interested to see if that fix works, not sure how taking the DB off line then back would be a long term fix though?
Just an update, we are still testing out and haven't officially taken the plunge yet (yep a year later) but to the best of my knowledge this error is no longer happening and to be completely honest, I have no idea what we did to fix it anymore or if a bug fix was patched on. I have always been in online mode, so archiving wasn't my issue and I never saw the error mentioned above.