Every time I exit (window close, ALT+F4) Firefox Quantum, a few seconds later the crash reporter pops up. Nothing problematic about Firefox itself, just does this upon exiting. (Submitting the crash report always fails, too, so it's not worth bothering with.)
I just X out of the crash reporter and I haven't been worried about it, but thought I'd drop a note here.
Windows 10 Pro 1703 (work computer), 64-bit. Install path is default, and it's an upgrade. I've had Portable Firefox on my drive since I don't even know when.
FWIW, the support page is woefully out of date. References to Firefox 2... I did skim it, though.
Firefox Portable English 57.0.2 running in 64-bit mode closes out without issue using ALT-F4. Please include 32-bit vs 64-bit and language. Please try a fresh install of Firefox Portable to your Desktop directory to see if it also has the issue. Additionally, are you launching additional URLs or HTML files from external sources? If so, are you calling firefox.exe directly or FirefoxPortable.exe?
The crash reporter is purposely disabled in Firefox Portable. It is not portable.
The change logs on the support pages are not maintained and are being removed.
Sometimes, the impossible can become possible, if you're awesome!