I currently do not have any wheel encoders plugged in.
I also get the following errors. In prev versions I did not
[ERROR] [1513135152.385718905]: FCU: GPS positions differ by 93.2m
[ WARN] [1513135152.386053606]: FCU: Flight mode change failed
I had 2 gps systems plugged into the navio2 when I was getting the errors above
(Reach RTK and standard GPS that comes with the Navio).
I have since disabled GPS1 as I would only want to to use the solution from the RTK GPS (GPS2). In this instance I don't think there is anything for you to solve. I just thought I would put it on here in case people see the same messages while using 2 GPS modules