My default browser is Chrome, but when I occasionally use Firefox for whatever reason there is often an update to it.
Almost every time I update Firefox some of my add-ons become incompatible.
Why is that?
Why doesn't this happen in Chrome?
I hear you! I ran Firefox today for the first time in ages just to use one addon - it then said an update is available - I let it do this, and then, all my addons got disabled!
Firefox updates do not actually mark individual addons as incompatible per se, it is the addon authors not stating that they are compatible which disables them.
You can use the add on compatibility reporter which will allow you to use addons which are not "compatible" with your Firefox version.
As for why Chrome doesn't do this - I think it is subjective and you will get different answers - IMHO, it is designed in a more traditional way - it allows all add-ons and if anything breaks, the onus is on the user to find the error where as by disabling until they know it is safe, Firefox may annoy the average user, but, is a safer solution to the end user.
Each addon in Firefox has setting which specifies which versions of Firefox it will work with (the presumption is that the author has tested their addon with the versions mentioned). Historically, addons typically claimed compatibility with a major release of Firefox (e.g. 2.X) but then there were problems with differences between 3.0 and 3.6 so addon authors got more specific and only claimed compatibility with particular major and minor versions (e.g. 3.6.X). A range of versions can be specified (e.g. 2.X -> 3.6.X) but an upper limit has to be given and it can't be an unreleased future version of Firefox if you want to distribute your addon via the Mozilla site.
Now that "major" versions of Firefox are being released every 6 to 8 weeks (we've seen versions 4.0 through 6.0 since March) addon authors just can't keep up and more and more are falling behind.
You will occasionally see a message on the Chrome "Extensions" page saying that a particular extension needs to be updated to work with the current version of Chrome but, since updates are done automatically in the background, it's hard to catch one in this state.
If this annoys you that much one fix is just to not use esoteric or unpopular addons. In any add on system plugins will go out of date eventually. Unpopular, abandoned, or people's pet project addons rarely get updated to use the new API available in a new browser.
I have been using the same set of addons for years and have only once got an incompatibility error. My list:
All of these addons have worked for years without any problem. What do they have in common? They are popular.
Honestly the recent Firefox bashing because they are using someone's addon that doesn't work in a new version of firefox, when the addon got created on a weekend for some miniscule functionality and published just to give their name some exposure, is getting really old. Popular addons have always worked, use them. If your using an addon that 5 people have downloaded, then your on your own