A workaround which I've just used is to replace LastVersion in your profile's compatibility.ini with the one that the current version of firefox uses (70.0.1_20191031000133/20191031000133).
(I suspect in the short term this could be fixed by a no-change rebuild of firefox.)
A workaround which I've just used is to replace LastVersion in your profile's compatibility.ini with the one that the current version of firefox uses (70.0.1_ 20191031000133/ 20191031000133) .
(I suspect in the short term this could be fixed by a no-change rebuild of firefox.)