[Request] まいが/My Girl PINKBELL SOFTWARE

I'm experiencing the same issue with the game crashing on startup, but I don't think the problem is the download itself. Try it yourself: see if you can run the trial version of the game, which you can find on the dlsite link you provided.

The one solution I know of is to copy main.swf from data into the main folder (same as your mygal.exe) and run it (in a browser, for example). You wouldn't be running it as intended, but at least it works.