I installed a 787-9 Scoot Airways addon, the creator was TDS and I downloaded it from Simviation. Originally it needed the Qualitywings 787-9 virtual cockpit but the one I downloaded has the stock 737-800 virtual cockpit which is fine for me. I also downloaded a fictional Qantas 787-9 to use as the base pack and just added the Scoot texture. The virtual cockpit on the Qantas worked, displays, panels etc. But in the Scoot virtual cockpit everything was black except the displays, EICAS etc. Some buttons and switches on the overhead panel were missing. I tried fixing it but nothing worked.
Thanks in advance
*Edit: I'm using FSX Steam Edition, every other aircraft works.
Check on the Steam forum and see if this one works with the Steam version.