I'd like very much to fly the DHC-6 Twin Otter and have tried three different versions of the aircraft model, but each one has errors. In general, either the windscreen and windows are grayed out, the panel instruments are grayed out, or both. The version I'm using now, it's the windows. I've attached a screenshot that shows both the issue, and the Log file where it specifies errors in finding the various glass effects files (although some of them are present in the model folder).
The first model came from GitHub and was called dhc6-master, the second came from the Legacy downloads page (instruments and windows grayed out), and the third model, which I am currently trying to use, came from pattenflightgear.wifeo.com (windows grayed out).
I am very new to FlightGear and would appreciate any help.
OS: Linux Ubuntu 14.04 LTS
FG: v3.4.0
Graphics: Intel integrated
Only certain aircraft, any location
No output to the console