NSM 7.0 does not support heterogeneous environments. Sensors should be on v. 7.
Upgrading the sensor to v.7 should resolve this problem.
Its strange as one of the sensors is 4010 and this had no problems to manager v7 but 3 2700 device gave this error.
question so if the device is managed by NSM 6 can you upgrade the sensors to V7 using the old manager?
NSM 6 cannot upgrade sensors to v.7
NSM 7.0 will be able to push the v7 software to the 6.x sensors.
So going forward I should manage the sensors with V7 and then upgrade all sensors running V6 to 7