App says "Data folder missing." I have the data folder, how do I use it to open the application?

try:

drag and drop the data folder on the Application icon.

In general, Applications should be located in the shared /Applications folder. Each user get the equivalent of private access, because they each have their own private settings files. Options one user chooses do not affect any other user.

if they are not to be shared by all Users, you can create a private Applications folder under your User folder.