macOS users must right-click on the tinyMediaManager.app, choose Show package contents and navigate to Contents->Resources->Java to find those folders.
Copy the folders data and cache from your v3 installation over to the v4 installation.Extract the archive to your preferred destination.
The first way (preferred at the moment) would be to download a fresh copy of tinyMediaManager from and copy over your data from the v3 installation to the new v4 installation. There are two different ways to upgrade an existing tinyMediaManager v3 installation to v4.