I have two xv-21 neatos, one is several months old (worked flawlessly up until recently), the other one I bought about a month and a half ago.
The older one randomly got the wheel stuck error.. sent it in, got a new one, worked fine. My 2nd neato then got a stuck wheel shortly after getting the replacement for the first one.. sent that back. got a new one... now the last replacement I got again has the stuck wheel error.
So, in short, in about 2 months time, I've had 3 neatos give me the stuck wheel error. I love this thing when it works, but I fear it's just going to be a paperweight once the warranty is up. Any idea what keeps causing this? I'm looking in the wheels and there is absolutely nothing jamming them.. but one wheel (the left each time) just becomes more difficult to turn. Very upsetting after spending $800+ on these things