‘There were no licensing issues, the platform was quite alive, yet developers didn't move, why?‘ I’d suggest one of the reasons on Xplane was the huge difference between 10 and 11. The difference between add ons for 10 and 11 is huge. In your earlier response about the work, building assets etc. if there’s no bridge back to the older sim, was interesting. The question there is does that just delay third party developers or does it mean that you aren’t going to see them - that is having to build everything up from scratch is just too costly. Perhaps that’s another answer. When DTG moved to TSW they cut all of the third party vendors adrift. Rivet, as a second party developer ( rather than third) might of course have access to some of DTGs work and therefore don’t have to start from zero.