Login screen displays 'Service Unavailable' or 'RoundTrip is denied database access'

Problem

When you try to log in to your GpsGate server on the main login screen, you receive the error message 'Service Unavailable'.

If you run an older version of GpsGate you might see the error slightly different as in the image below:

Symptom

When you check the error logs (in your own server, the error logs are usually located in C:\GpsGateServer\ErrorLog) you'll observe 'RoundTrip is denied database access' error(s).

Solution

1. Stop Franson NMEA service (Services panel usually located under Control Panel > Administrative Tools).
2. Delete the file on C:\GpsGateServer\Franson NMEA Service\BlockEnabled (if it exists).
3. Start the service again.