Can't use file picker on Firefox Dev edition 70.0b macOS 10.11.6

I hope this is the right place to post.
I couldn’t use the native filepicker for uploading a file on .
Everytime Firefox crashed or froze.
Firefox Dev edition 70.0b, macOS 10.11.6

you mean when clicking here?

it does work for me

Yes, I’m talking about this. I don’t think it’s related to the site though