Hello, I'm sorry to hear it's not working for you! I'm happy to help and will try running v50 of Firefox tonight. You can always report issues on our Github page, https://github.com/MisterPhilip/omnibug/issues and I'll work on getting more documentation available for end users.
Update 2018.01.12: we've added a help page with more information, https://omnibug.io/help