Issues with the SD card itself are a common source of trouble. If you encounter strange problems like missing files, folder errors, or continuous installation failures, a corrupted SD card might be the cause. Tools like h2testw can be used to scan an SD card for errors and ensure it's functioning properly before you begin any installation.
Despite the official cancellation, the OMORI community has found a way to bring the game to the 3DS through unofficial means. The key lies in a fan-made demake called . Omori 3ds Cia