Hello @Ivan_Cheng welcome to the community!
I am not a developer or expert on installing OpenEMR but I do customer support of OpenEMR and have been reading this forum for a long time. I notice that you are making a large jump in versions, and I do know that many fundamental changes have been made in the OpenEMR codebase between those versions.
Updating between very different versions is not a simple process. Normally users will apply a long series of patches to bring their installation up from one version to the next. Or if you are trying to preserve the database you can export the data, install the updated OpenEMR version then re-import the data. However, you’d need to accommodate the changes that have been made in the database structure between the versions, and other considerations like new php versions, etc.
You might try searching this forum for what other users have done, with a search such as:
https://community.open-emr.org/search?q=upgrade%20from%204%20to%207
or change the wording for a better focus.
Good luck, and feel free to come back to the forum with more specific questions.
Best- Harley
