1.5.4 on firefox 44 Cant select directory

[DanaMW]

On neither my windows 10 or fedora box can I select or change the sage feeds folder. It just pops up with a blank selection box.

[RDL-github]

I also see this problem with Sage 1.5.4 in FF44.0.2 x64 on Win 7 x64

[murdos]

I confirm this issue with Sage 1.5.4 in FF44.0.2 x64 on Win 7 x64.
Is there a workaround, e.g. setting manually a key in about:config?
Because in the current state the extension is not usable at all.