Restoring Original Shader Files Help

I have been experiencing problems with my weather in Active Sky Next whereby I see accurate clouds and weather below 10,000 or so but when I fly at say 25,000 feet and above and the weather gauge shows clouds below together with precipitation all I see is clear ground and no weather,also had the same issue with Opus.

The Active Sky team have been very helpful and have tried everything but they have come to the conclusion that I have an issue with my shaders and that I need to restore the original shader file.

Now,I am not sure how to do this and where to go from here and if I can help it I really do not want to uninstall and re-install FSX.

I should therefore be obliged if someone could  assist me please.

Many thanks in anticipation.

Michael