While I think it's possible that in SOME cases the XML file itself might be a problem, there's still an underlying issue with MSFS not loading the file, regardless if it's correct or not, because it's wrongly trying to verify the license also for the child processes, in addition to itself.
Something it cannot be able do, since none of the .exe you'll eventually start from there would use the MS Store license, either because they are freeware (like Honeycomb drivers), or because they have their own licensing system ( Fenix, GSX )