GSX never opened any door, or had any effect of the opening of the doors. Since the first GSSX release, you are always supposed to open the doors manually, and this hasn't changed.
Nothing in the GSX installation can have any effect on your ability to open the doors on a particular airplane, which will continue to work just the same, regardless if GSX is installed or not.
If, instead, with "I cannot open any door", you really mean: "I can open doors, but GSX doesn't detect if they are open", that's an entirely different issue, but it doesn't seem like that from what you wrote.