Most of the compatibility issues I've seen around Windows apps that fail to work seems to be changes/updates around security. A big one that I saw in the past

Most of the compatibility issues I've seen around Windows apps that fail to work seems to be changes/updates around security. A big one that I saw in the past around XP or 7 was that your general applications could no longer write to their Program Files location by default... there are many others over the years. MS has made a fair effort to maintain compatibility, but don't underestimate the power of developers to hard code something out of convenience that bites them in the rear once security contexts change from under you.