Please what does that mean? From my test issue with Eversync has been the same on Mozilla Firefox (older version) than on Palemoon (latest). And the add-on still says

« Firefox 4.0+ Compatible » :/

Coming back; have you got some news on the Mozilla Firefox versions that EverSync supports please?

Yes super ! That'll show EverHelper takes support seriously. Be sure II'll mention it on a paper I'm writing about Bookmarks Synchronizers.

Same issue on Firefox 18 ES-6.6.3: "Account" tab is empty.

Same issue on Palemoon (Firefox 25) with ES-5.6.4.1-signed and 6.1.0: Initialization...

My verdict is that this add-on is not compatible with Palemoon-stable nor with any older version of Firefox/forks, on contrary to the stated "Firefox 4+"

Same than Marco here https://fvdmedia.userecho.com/topic/908316-bug-setting-account/