It was working fine for 3 weeks. Then it kept causing firefox to slow down and crash. Worked great otherwise, please fix this issue.

Can I have the old version back ?
this new update (on july 6, 2020) is a lot slower and make text selection impossible on some pages, as it makes the highligh selection to show only after 2 to 3 seconds
--- update ---
Finally, after testing all combinations, it seems that it is a Firefox issue more than coming from this extention. I uninstalled all plugins/extensions and I still had the issue.
But it doesn't explain why it was working a day before while this was the only extension that had an update on the 7th of july.
Also, it doesn't explain why the "Owl" extension solves the issue when activated.

Perfect add-on. Now fast enough for daily usage

Good ADD-ONS

GMail still fails, rachelbradleycomedy.com fails, and slows down loading pages sometimes a lot, you only need to manage the background when it's white or really bright/near white, or at least offer that option, the res of colors are mostly OK. For future upgrades: allow me to select on a webpage what colors I find it too bright, and to be reported back to you, to know what people want from this app, and allow my preferences to be stored on Google Drive or any another cloud for when I reinstall Windows please. Uninstalling too slow, 1 star, until you improve, looks like you make a lot more than just make everything dark, you don't deserve my trust