The message we are seeing is:

Qt Code: 
  1. QFontDatabase: Cannot find font directory /opt/Qt5.1.0//5.1.0/gcc_64/lib/fonts - is Qt installed correctly?
  2. Aborted (core dumped)
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We've tested with numerous -platform plugins so it does not seem to be platform specific. To get around the issue we simply create that directory and the application launches fine and we don't see any font related issues etc.

The problem now comes when we are deploying the application. When running our deployed application it crashes again if that directory does not exist. The installers can create that directory but it feels a bit silly to do that and it requires sudo rights to create it.