First.... a "bug" is a code problem NOT an icon issue
Second.......it's showing an Icon in my game and the virgin copy I keep for testing patch installations ( shown here ) so the "bug" is at your end
The file the Icons used for that vehicle is Icon0105.shp....check you have one in your graphics folder and it's full and has been since version 5.5 so if you are missing the ones for the Vierba you are missing many more as well but I can assure you those Icons were issued and are in everyone else's game