I don't believe this is an openSUSE issue, but many here seem to use Firefox, so a heads up.

I have noticed that the latest barrage of Firefox updates has resulted in broken (incompatible) add-ins, at least when the new versions first appear.
It also seemed that Sync was broken, which had me chasing DNS issues for a while as their online status reported DNS propagation issues.
I really like Sync, it keeps my bookmarks available across several Linux machines and Linux and Windows VMs.

So when DNS did not really seem to be the issue, I stumbled on some web references to sync logs.
They can be viewed at about:sync-log in Firefox. the sync application started life as weave.
In reviewing some of my logs, I could see that sync was crashing attempting to Sync Add-Ins.
The results of these crashes seems to be that other changes(e.g. bookmarks) have not been propagated properly to the sync server.

My suggestion - if you use Firefox-Sync, turn off Add-In synchronization until Mozilla sorts this out.

I am searching for the right forum in Mozilla to report this.