Richard,
i was restore from original back up but unfotunately PTA says:
Check shaders integrity...
ERROR: shader file C:\Prepar3D v3\ShadersHLSL\Cloud.fx is not original Prepar3D shader and can't be used.
ERROR: shader file C:\Prepar3D v3\ShadersHLSL\GPUTerrain.fx is not original Prepar3D shader and can't be used.
and the clouds are black
...