Thanks for building this time with the " --disable-accessibility" flag...
I had commented:
Upon testing, it appears that the latest Serpent 52.9.0 (32-bit) (BuildID=20200925161000) remains unaffected by that bug, which is, hence, only manifested in latest New Moon 28.10.2a1 (32-bit) (BuildID=20200925153118); but my initial assessment was correct - upstream commit
https://github.com/MoonchildProductions/Pale-Moon/commit/9f56811e04ef4703aec82ba6a7c712e50c7667c0
was indeed the one that broke the native downloads manager... Moonchild became aware and later authored:
[downloads] Correct and simplify host handling.
https://github.com/MoonchildProductions/Pale-Moon/commit/fd30b23a0dfa2373539b348519aa9864976b46dd
... but, alas, it came too late for "us" , that one was not included in
https://github.com/roytam1/UXP/commits/custom
when latest NM28 was compiled...
I have confirmed that the "fix" works as intended, restoring the functionality of the native NM28 Downloads Manager, as well as the functionality of the (legacy) Downloads Window extension several users (including yours truly ) have installed...
I understand, your spare time allowing , that the fix will be included in next Saturday's released builds, in the interim I have taken the liberty of modifying and uploading a patched omni.ja file latest NM28 users could download to regain lost functionality:
omni.ja
https://www119.zippyshare.com/v/lAv8DFrY/file.html
It should be placed inside
"./palemoon/browser/"
overwriting original omni.ja file (or you could rename/back-it-up first, e.g. as omni.ja.BAD) ; hope I've helped!