You downloaded a USA base game CIA (Title ID ending in D9400) last year. You beat the first three labyrinths. Now, you find a Reddit link to "All DLC Pack.cia" but it is tagged EUR . You install it anyway.
: A quest providing an accessory that increases enemy drop rates. Audio Options Etrian Odyssey Nexus- DLC 3DS -EUR USA- CIA
: Features portraits based on other Atlus properties, including characters from the Shin Megami Tensei series. Regional Differences & File Formats You downloaded a USA base game CIA (Title
While the 3DS is natively region-locked, the following applies to DLC and game files: What was the DLC again - Etrian Odyssey Nexus - GameFAQs Etrian Odyssey Nexus- DLC 3DS -EUR USA- CIA