1. Ensure that you are not using any RT extensions (e.g. roksprocket etc) If you are you will need to replace them all with a Gantry 5 particle first (there are plenty to choose from).
2. Make sure that all your third-party products are compatible with Joomla 4.
3. Backup Backup Backup!
4. Update Gantry 5 to latest version v5.5.7
5. Update the Callisto theme to the latest version v1.5.0
6. Go to Gantry 5 menu editor and save each of your menus therein.
7. Clear server and browser cache.
8. Test your site and make sure everything is still ok.
9. Backup backup backup!
10. Go to components > joomla updater and click the "Options" button top right and change the update channel to "Joomla next".
11. Now the update to joomla 4 will show - check all the messages and make sure everything is compatible. If it is, you can proceed with the update.
12. Clear browser and server cache.
13. Test your site again and make sure it all still works.
14. backup backup backup!
Regards, Mark.
Please search forums before posting. Please make sure your post includes the version of the CMS you are using and a link to the problem. Annotations on screenshots can also be helpful to explain problems/goals. Please use the "secure" tab for confidential information.
Please search forums before posting. Please make sure your post includes the version of the CMS you are using and a link to the problem. Annotations on screenshots can also be helpful to explain problems/goals. Please use the "secure" tab for confidential information.