Hi!
You are receiving error code 999115448.
There are two reasons that the system returns error code 999115448:
1.If the CU client is located in the internal LAN, the user logs in to the CU client using the service IP address of the master domain server and the NAT IP parameter of the MPU server is null or incorrectly set.
2.If the CU client is located in the external LAN, the user logs in to the CU client using the NAT IP address of the master domain server (specified by NAT IP) and the NAT IP parameter of the MPU server is null or incorrectly set.
Please check if the NAT IP is correctly set and use the floating IP address or NAT IP address of the master domain server to log in to the CU client.https://forum.huawei.com/enterprise/en/corpus-15949.html

Hope it helps!