Update your Luma3DS install to the latest stable version and make sure "Enable Game Patching" is enabled.Plug your SD into your computer instead of using FTP or MicroSD Management for best results. Try deleting the files from SD:/luma/titles and re-copying them over to the SD.Make sure you have properly removed any SaltySD-based hacks from your 3DS SD card as detailed at the top of this post."HELP! I get a black screen or crash dump error when I click Ultra Sun / Ultra Moon when using the Drag & Drop install method!" You can now delete your dumped ROM and your Extracted_ROM folder.Booting Ultra Sun or Ultra Moon should load Supernova Sun or Penumbra Moon with randomized wild encounters.For reference, the Title IDs for Ultra Sun and Ultra Moon are 00040000001B500000001B5100 respectively. If there is no "8" folder inside romfs/a/0, create one. Once you've randomized your Wild Encounters, copy /Extracted_ROM/romfs/a/0/8/2 and /Extracted_ROM/romfs/a/0/8/3 to the /luma/titles/16DIGITTITLEID/romfs/a/0/8 folder on your SD card.When you reach the part where you can randomize your wild encounters, say Yes and use PK3DS to randomize them.
Pokémon Supernova Sun and Penumbra Moon are mods for Pokémon Ultra Sun and Ultra Moon.