Working on this for my colleague …I transferred all files from the old host to the new one. All PHP versions correct with the right extensions etc. Kirby was updated at the same to version 4.1.1. The site delivered OK (www.mickconefrey.co.uk). However, the panel is missing several sections for editing and I can’t really see where to get those back? Should I try to re-install the panel (how?). I cleared the cache, deleted the media folder. Any thoughts?
Edit: I have reverted back to Version 3 for the moment.
If you want to update to Kirby 4, you need to make sure that the project is ready for it, i.e. plugins need to be updated (if used and if updates are available) or replaced with native features, also any other custom code that you are using.
For details, see the release page for Kirby 4: Kirby 4 | Kirby CMS