I use a multi-browser environment -- Brave, Chrome and Firefox. For the most part Firefox but the 64-bit counterpart, which is Palemoon. Others would debate and say Palemoon is not Firefox, my take is "whatever makes you happy".
For me, when websites don't work on Palemoon, that's the time other browsers come into play.. The point of this is: How to force extension compatibility between Firefox and Palemoon.
Palemoon doesn't follow the same versioning as Firefox, so even though there is no compatibility issue with the extension, it will not install the conventional way. But it will still install, here's how.
This post will make use of DownloadThemAll! (or DTA) since this is one of the major reasons why I stick it out with Firefox (or Palemoon). Trying to install it on the website, this is how it will look on Palemoon.

Right at the bat, the compatibility check fails and the add-on could not be installed. That is what I mean by unable to install the conventional way.
You can, however, right-click on the [+ Add to Firefox] button and save the link. Rename the file downthemall-3.0.8-fx+sm.xpi into downthemall-3.0.8-fx+sm.rar. As of this writing, the version of DTA is 3.0.8. Then open the downloaded file in WinRar (or another software that can read and write to .RAR archives).
Extract the file install.rdf.

Edit the extracted install.rdf in your favorite text editor. Replace these lines..
<em:minVersion>45.0</em:minVersion>
<em:maxVersion>51.*</em:maxVersion>
.. to..
<em:minVersion>25.0</em:minVersion>
<em:maxVersion>51.*</em:maxVersion>
Then replace the original install.rdf with the edited install.rdf on the .RAR archive. Rename the extension downthemall-3.0.8-fx+sm.rar to its original filename downthemall-3.0.8-fx+sm.xpi and drag this file to the Palemoon browser. This action installs the extension, and simply answer Install when asked.
A fellow asked this question earlier, and I will be sending him a link to this post, with the intention of helping others who are looking for the same answers.
I have tried this on DTA and several other extensions. Your mileage may vary.
(images and screencaps are mine)
If you happen to find this post helpful, send me an upvote, or resteem this post, or buy me beer by these wallets. Thanks in advance.
- #Bitcoin (BTC) - 3Kyjg1Wj1PNGN3KhiRprxYvvQpdjC5kT3k
- #Etherium (ETH) - 0x5F168F895C63ccC5FbEf921047bc2b63f6780c3F
Thanks! (vote for them as witness!)

Sponsored ( Powered by dclick )
Introducing DCLICK: An Incentivized Ad platform by Proof of Click. - Steem based AdSense.
Hello, Steemians. Let us introduce you a new Steem B...

This posting was written via
dclick the Ads platform based on Steem Blockchain.