Preparation pointers for a 3.4.5 to 4.x migration

Hi all, I’m running an OpenHabian OH 3.4.5 on a Pi 4, thinking it might be time to upgrade it to the latest stable version, which seems to be 4.2.3 . I use MQTT, ZWave, TPLink Smart Home, Wiz Lighting, Nanoleaf, Exec, OpenWeatherMap, Pushover, Systeminfo and WLed bindings. Aside from that I use NodeRED extensively.

Any specific things I mind as I prepare to migrate? Any of the bindings above suffered a significant change? Any concern with NodeRED or MQTT?

Thanks

Can‘t comment on all Bindings you use, but You should wait another week until openHAB 4.3 will be released….

If you can’t wait as @hmerk recommends, I can suggest to at least upgrade to OH 4.3 M4 now and in a couple weeks when 4.3 release comes out upgrade again. The differences between 4.3 M4 and 4.3 Release will be tiny and extremely unlikely to cause you any problems.

To learn about each of your add-ons I recommend reading the block posts and the Announcement threads for each of the release between 3.4.5 and 4.3. All the major changes made to each binding is reported in the change log linked to by those threads. But the change log is not cumulative, this means they only cover the changes between the previous version and the new version. So to see all the relevant changes, particularly the breaking changes, you need to review each in turn.