Errors in bgfx_??? module:

-1	NVDI not installed
-2	Cache dir does not exist
-3	Error building cache
-4	DIMG not located in Thing config
-5	DIMG file does not exist
-6	DIMG file is smaller than current screen size

Errors in icon_md? module:

-1	General error
-2	Cache dir does not exist
-3	Error building cache file
-5	RSC file does not exist

Errors in ipng_md? module:

-1	NVDI not installed
-2	Cache dir does not exist
-3	Error building cache
-5	PNG files not found
