When running the launcher on OS X, it deletes everything when it self updates. It is storing the save files, installed modpacks, and downloaded Minecraft versions inside the .app package, which gets entirely replaced upon update.
The standard location for custom application data on OS X would be ~/Library/Application Support/FTBApp/, and the user's data that should not be lost should be kept there.
When running the launcher on OS X, it deletes everything when it self updates. It is storing the save files, installed modpacks, and downloaded Minecraft versions inside the
.app
package, which gets entirely replaced upon update.The standard location for custom application data on OS X would be
~/Library/Application Support/FTBApp/
, and the user's data that should not be lost should be kept there.more details available here https://github.com/FTBTeam/FTB-App/issues/90