When trying to add the 'Stealth Mastery' as a Shadow Mystery Revelation (for Oracles), it gives the following error message:
Failed to add Ability due to Cannot ask for contains: pcgen.core.Ability Reference Skill unlock ~ Stealth has not been resolved. See log for further details.
It will still add it to the Selected Abilities table, and will still be printed onto the character sheet, and even allows the character to be saved. However, when loading the character later, it gives the same error message and thus does not load the character.
I have added the log output as an attachment. This was done in PCGen 6.08.00 RC8. Loaded sources are:
Advanced Class Guide
Advanced Player’s Guide
Advanced Race Guide
Blood of Shadows
Pathfinder Player Companion: Blood of Shadows