After spending several weeks migrating my openHAB setup from version 2 to 3, I wanted to share my experience and some tips that might help others avoid common pitfalls. While the process had its challenges, it’s been incredibly rewarding to see how much smoother and more efficient OH3 runs compared to OH2.One of the first hurdles I encountered was the Cannot create a duplicate value 'newState' error when working with expire items. After some research and reaching out to the community, I discovered that this was related to how expire items are handled in OH3. I had to adjust my item definitions and rule logic to accommodate these changes. For example, I had to remove the expire parameter from my item definitions and instead use the built-in OH3 functionality for expiring items. This was a bit of a learning curve, but it ultimately made my setup cleaner and more efficient.Another thing I struggled with was running openHAB as a service on my Windows machine. I received the dreaded error 1607, which was quite frustrating. After some trial and error, I realized that the issue was with the wrapper.config file and how it referenced KARAF_HOME and KARAF_BASE. I had to manually set these variables in the system environment, which finally allowed openHAB to start as a service without issues.Throughout this journey, I’ve learned a few key lessons:- Backup everything: Before making any major changes, always back up your configurations and item files.- Take it one step at a time: Migrating from OH2 to OH3 isn’t something you can do in one go. Break it down into smaller tasks, like updating one binding or rule at a time.- Leverage the community: The openHAB community is incredibly supportive. Don’t hesitate to ask for help in forums or Discord if you’re stuck.I’m now fully operational on OH3 and loving the new features and improvements. My setup is more stable, and I’ve noticed a significant reduction in rule execution errors compared to OH2. It’s also been great to see how the community is continuously improving OH3, making it even better with each update.If anyone is considering migrating to OH3 or has already started, feel free to reach out! I’d be happy to share more specific tips or troubleshoot issues together.