Question

I've recently upgraded to Studio One 4. For some reason, VocAlign Project shows up in Studio One 3, but does not show up in Studio one 4. The VST Plugin locations are the same

Answer 1

https://www.synchroarts.com/faq/studio-one-4-does-not-show-the-vocalign-project-or-vocalign

Answer 2

I had the same problem. This troubleshooting from SA fixed it.

Windows

1. Exit Studio One Professional software (if it is running)
2. Open a Windows Explorer window
3. In the address bar, type:   %AppData%
4. Open the PreSonus folder
5. Open the Studio One 4 or Studio One 5 folder (as applicable)
6. Open the x64 folder
7. Delete Plugins-en.settings
8. Launch Studio One Professional again

macOS

1. Exit Studio One Professional software (if it is running)
2. switch to the Finder
3. in the Finder, go to the Go menu and choose Go to Folder… 
4. copy this address exactly as it is:   ~/Library/ Application Support/Presonus Software
5. in the Go to the folder: window that will open, paste:   ~/Library/ Application Support/Presonus Software
6. in the Presonus Software folder, open the Studio One 4 or Studio One 5 folder (as appropriate)
7. in the Studio One 4 or Studio One 5 folder, open the x64 folder
8. in the x64 folder, delete Plugins-en.settings
9. Launch Studio One Professional again