User Portal not accessible internal

Dear friends,

i will have to Access to the user Portal of my UTM 9.3 but there are errors related to SSL. As i Access via browser to my ip-adress of the utm, the error in samle Firefox said to me: " error secure connection failed"

When i try to use SSLv2 and SSLv3 additionaly the error are always been there. But when i go to the UTM admin-Portal, there are no errors and in the certificate settings there are a WebAdmin Certificate with an VPNId by Hostname.

Can anyone help me to troubleshoot this Problem. I dont't understand why i can't Access to the user Portal.

Thanks for all