Verify that the Sensor software image, Manager software version, and signature set version are compatible. This information is provided in the release notes that accompany each product release. The Manager version must be higher than the Sensor software version. Recommend that you refer to the release notes of both the Manager and Sensor software to verify compatibility.
Consider that your Manager version is 10.1.7.61 and the Sensor is an NS-series Sensor on software version 10.1.5.190. Version 10.1.5.190 for NS-series Sensors was released after Manager version 10.1.7.61. By referring to the release notes of Manager 10.1.7.61, you can verify whether Manager 10.1.7.61 can manage an NS-series Sensor on 10.1.5.190.