OS: Windows 7
Version of C2: Release 163 (64-bit)
What is OS rights to export location? I also program with GameMaker, and I've never had any problems creating games with that.
Minify: It won't allow me to select that when exporting to Scirra Arcade, but on HTML5, it's automatically checked.
Maybe reinstall c2 can help, or if you are really using r163, try to update to r173, this may help, i hope. Oh, and launch c2 as administrator, and save your project to the location that has no access limit, like desktop.