Hello,
Handling Process
1. Check if connection between SM and database is working.

2. Check if Agile Controller services are running.

3.Add the Agile controller page to trusted sites on internet options > security > sites
4. Checked tomcat logs, and we have found that an error “not enough resources” was found
Root Cause
Not enough memory and cpu resources were available on the server were Agile controller was installed in order to open the web-gui.
Solution
We have stopped and started Agile Controller SM, doing this does not impact the services as we did not stop the services of SC.
You will find Server Startup Config in the directory where Agile Controller is installed.

Suggestions
Suggested to customer to upgrade the resources available on the server to avoid this issue from appearing again.
Detail
https://support.huawei.com/enterprise/en/knowledge/EKB1001881709
Thanks