Cause of Relay Coil to stop working ( No resistance) can it be fixed?
The coil should be much lower than 9M, 9K DC resistance is plausible. 

It is a power relay and will wear out in use, rating is 100,000 operations only, however the coil should not fail (go open) under normal conditions.

If the relay is exposed to corrosive environmental conditions such failures can occur.