I don't know how many times I need to emphasize the right way of investigating this issue.
_mental_ wrote:None of the provided reports didn't answer one simple question: was the config screwed during exiting from the first run or did it happen at beginning of the second one?
_mental_ wrote:If it's blocking file from reading, and then, it allows writing to the same file, we really need to know more details about this.
What you need to do is to keep GZDoom running (or kill it from Task Manager to avoid writing the config file), copy .ini to other location, and make sure that last modification time is preserved.
Now you can figure out was the config already screwed or not. This way, we will have an answer to the question from my first quote.
And once again, if this happened to you, it's completely useless to just post about the fact. Doing this won't make it fixed any faster.