@HInoue Fixed the bug you mentioned in #290](Dungeon Architect - Work in Progress - Unreal Engine Forums)
Due to the newer optimizations in the instanced mesh scene provider, a hash is generated and saved for each node in the theme file. So the older theme files had to be re-saved. The theming engine now regenerates the hash if it is not available so it works with older theme files
Edit: Fix will be available in 1.1.3. In the mean time, just re-save your old theme file if you face this issue