Dear friend!
The possible causes are as follows:
1. The communication between the NMS and the NE is abnormal. Check whether the optical cable or ECC link is normal.
2. The NMS account rights are restricted, and the NE account or password is incorrect.
3. The license file does not contain the data of the NE to be added, or the license file is incorrect.
4. Duplicate NE IDs.
5. The process managed by the NMS server is not started.
For more information, please click Creating NEs
Thank you!