How to share a project between computers

So I wanted to share a project to another computer and open it exactly what the main computer does. I have copied the project files included: content, config, saved, and unreal project file to a Dropbox shared folder.

Then, I downloaded it from another computer. When I open the unreal project file on the other computer, the content, maps etc disappear and I can only see a blank floor. Someone please advise.

Thanks in advance for any help

Zip it:

Or just copy the entire Project Folder - but that will be quite chunky.

When I zip up and open the project, it also shows a blank floor only…