I'll add my two cents here since I was also hitting this. It was giving me this error (which I think was a false positive) simply because I wasn't encoding the data correctly. I was trying to encode using a JSONEncoder when I should have been using a PropertyListEncoder. Here is a working code snippet: let encoder = PropertyListEncoder() let data = try encoder.encode(self.gameData) let savedGame = try await player.saveGameData(data, withName: "game.data")

We actually do have the value WKApplication: true set in the watch target's Info.plist. In addition, the application installs and works on iOS 16.1, iPad OS 16.1, and iPad OS 15.7, but it fails on iPad OS 14.8 and that's when we get this error reported. Here's a snippet from our main app target Info.plist: <key>CFBundleIdentifier</key> <string>com.ourcompany.ent.projectname</string> <key>MinimumOSVersion</key> <string>14.0</string> and from the watch target: <key>WKApplication</key> <true/> <key>CFBundleIdentifier</key> <string>com.ourcompany.ent.projectname.watchkitapp</string> <key>WKCompanionAppBundleIdentifier</key> <string>com.ourcompany.ent.projectname</string> <key>MinimumOSVersion</key> <string>7.0</string> We have been shipping a watch extension for the past two years, but it's only once we migrated to Xcode 14, turned off bitcode, and created a new single WatchKit 2.0 target (replacing the old WatchKit 1.0 extension) that this error arose.