I have the same problem with Orange Pi Plus 2:
Sep 5 18:09:40 localhost NetworkManager[553]: <error> [1504624180.7920] platform-linux: do-add-ip4-address[2: 192.168.1.34/24]: failure 17 (File exists)
Sep 5 18:09:40 localhost NetworkManager[553]: <error> [1504624180.8153] platform-linux: do-add-ip4-route[2: 0.0.0.0/0 100]: failure 3 (No such process)
Sep 5 18:09:40 localhost NetworkManager[553]: <warn> [1504624180.8155] default-route: failed to add default route 0.0.0.0/0 via 192.168.1.1 dev 2 metric 100 mss 0 src user with effective metric 100
I miss connection with orangePi (can't connect via ssh/vnc, can't ping), but internet still works on device. After rebooting everything is fine. This problem repeats every evening.
Is it possible to solve this without removing network-manager?
