Mozilla Co. may be circling the drain, but at least the latest Firefox Dev Edition beta broke the toolbar and bookmark bar and you can't downgrade 
@annika
Ha-ha-ha, yeah, I used to find myself in a situation like this one quite often in the past — that is why I remember it by heart… well, almost, it's actually even shorter, just "--allow-downgrade", right? 😅
@m0xee Top tip right there! Thanks very much
I still had to reset my toolbar to default but it seems to be working. (I did the same reset in one of the 132 betas but the problem came back. Not really up for messing with it more at the moment.)