Hi, Hummer!
The following information can help you.
1. Check whether the network IP address can be pinged. If the ping fails, check the network.
2. Check whether the web page address and port are correct. The format is as follows:
https://XXX.XXX.XXX.XXX:8443/sem
3. Check whether the SEM software is installed.
4. Check whether the user name and password are correct.