OS current-- "Emergency mode [], system logs,--"

Hi,
I am using Ubuntu mate in raspberry pi 3, it works fine but after writing some application with respect to server, after few days system will be in —

“Emergency mode [], system logs, systemctl reboot to reboot, system default or d to try again to boot into default mode.”

how to overcome with this problem. or how remove this problem.

i am writing python scripts and running in …/rc.local.

Did you try re-installing Ubuntu Mate?