This may happen when Java OpenJDK JRE fails to install by itself during the installation process of TSplus Remote Access. 

To solve the issue you need to install Java manually:

- download Java from here:

- unzip downloaded file in 'C:\Program Files (x86)\TSplus\Java' so that a 'Java\bin\java.exe' file exists.

Finally, duplicate the bin\java.exe file to create 2 new identical files,

and rename them into "SSHtunnel.exe" and "HTML5service.exe".

And reboot the server. 

Additional informations: 

TSplus Remote Access setup doesn't exactly install Java. It copies java files in a folder needed by TSplus web server.

Therefore you won't see the Java program installed on the system, as with the Windows Control Panel.

To know what is the Java version installed on your server, 

go to C:\Program Files (x86)\TSplus\Java 

and open the "release" file with Notepad :

In command line with CMD, you can also navigate into the C:\Program Files (x86)\TSplus\Java  folder and use the command "java --version" :

TSplus Remote Access update does not update Java, because it is time consuming, it is unnecessary and it could cause problems.