Upgraded from 4.5.1 to 4.5.2 and the config sync to the mesh nodes remains at ongoing forever and never completes, the nodes are a mix of AP903s and AP802. After a few hours frustrated troubleshooting i rolled back to 4.5.1 and everything is working perfectly again and they sync in under 30 seconds.
Seen the same reported on the Eire forum so its clearly a FW issue.