Unreal: Save Game to Slot fails on Quest

[tpg_sabibo00_qu]

On the Rift I use Save Game to Slot to save user data as outlined here: 

https: //docs.unrealengine.com/en-US/Gameplay/SaveGame/index.html

But on the Quest, the call to 'Save Game To Slot' fails.  Anyone know why it would fail?  Is there something you have to do before you can save user data on the quest?

[motorsep]

Do you have disk writing permission added to the manifest ? 

[tpg_sabibo00_qu]

Thanks for the reply. I got it fixed.   I'm not sure if itis the same thing as you are suggesting, but I had to 
make sure Use ExternalFilesDir for UE4Game files was enabled in the APK Packaging section.   Now it saves correctly.