As per the vendor, Type To Learn 4 (TTL4) is no longer being supported as of December 2016. As of this week, we have found that the TTL4 application on our student application server has stopped working and there is no fix to get it back up and running. The issue is because the software is pretty old (almost 10 years old) and the server it is running on can no longer support the application. Due to this reason, we will need to take TTL4 offline and won't be able to replace it with another system. Sorry for any inconvenience this may cause.
https://support.sunburst.com/hc/en-us/articles/204374117-Type-to-Learn-4-Network-Windows-Server-2012 Source: Sunburst Digital