What are you using (Windows, Android, Linux)? What error message or behavior occurs when it fails? Are your base game and update from the same region ?
Disclaimer: This article is for educational and archival purposes. Piracy is illegal. Only install CIA files of games you have legally purchased. The author is not responsible for console bans or data loss.
Are you using a or a digital/CIA version of the game? Knowing this will help me give you a more specific fix! Pokémon Ultra Moon does not run with 1.2 game update pokemon ultra moon update 12 cia work
:
: When creating your own CIA files from a game cartridge using tools like GodMode9, you might encounter a "Build Failed" error. The most frequent cause is insufficient space on the SD card. If space isn't the issue, try dumping your cartridge as a .3ds file first, then converting that to a .cia . What are you using (Windows, Android, Linux)
Second, region locking and encryption are persistent obstacles. A Japanese Ultra Moon update (v1.2) will not install over a North American base game. Users seeking a "working" Update 12 CIA must ensure matching (e.g., USA – Title ID ending in 001B00). Furthermore, CIAs are encrypted with a title-unique key. Custom firmware bypasses signature checks, but if the CIA is corrupted or improperly decrypted during dumping, installation will fail. "Working" releases from scene groups (like BigBlueBox or 3DSISO) have already been properly decrypted and repackaged.
Select the 1.2 CIA file and choose . Step 3: Verify the Version Disclaimer: This article is for educational and archival
If the update fails to install or work, use these proven community fixes to resolve the issue. Error: "Result code: 0xD900100A"
Many games, including Ultra Moon, require a "seed" to run correctly after updating. In FBI , select the game under Titles and choose "Import Seed" while connected to the internet.