OpsCenter Status Code "HTTP Status 503 - Servlet action is currently unavailable"

We had a vendor install the latest OpsCenter for us.  They have since come and gone and our team never verified it was working.  When we click on the web UI login we immedietly get the 503 status.  I'm not having much luck online in looking for possible remedies.  Would love suggestions on troubleshooting and correcting this.