Rufina,
It seems that the Domain Controller with IP 10.208.50.11 can't find the Service Principal Name `HTTP/vmedwboeweb1.PHS.ORG' that I understand it is the name of your Web Application Server.
This may be due because:
- Somebody has created a duplicated SPN with the same name and different account
- Somebody has deleted the service account or the SPN
- Name resolution problems for the DC 10.208.50.11
This seems to be a problem related to your domain resolution.
I will recommend you to use AD Explorer to find for duplicates or missing SPN.
Regards,
Julian