Hi guys, im new in this forum, and have a question to do here. Yesterday I made the downgrade my old 3DS XL in firmware version 10.4 following the tutorial video below: Everything went without any error , I did everything in my Kingston micro SD card 32GB. After completing the tutorial , I downloaded several .cias files related to games, created a " Games" folder at the root of the card, and copied the files on it . When I started the 3DS , and accessed the FBI application to install the files , I entered the "Games " folder I had created , but had no file inside the same . I returned to the computer and open the folder , and the file .cia really was gone. After this fact , I tried to copy the .cia file in the root of the card, and started the 3DS again to see if I could find the file in the FBI application. This time I could find it, and start the installation, but literally all .cia files that I tried to install , the following error appears : Install failed! Super Street Fighter IV - 3D Edition (U)... Source: SOURCE_FSFILE_WRITE (0X1c) Module: MODULE_NN_AM (0x20) Level: LEVEL_PERMANENT (0X1B) Summary: SUMMARY_INVALID_ARGUMENT (0x7) Description: DESCRIPTION_INVALID_SIGNATURE (0x6a) Please guys, help me! If I need to format the SD card, how I can do the whole process again , to be able to install the .cia files again ? Excuse me , I 'm really new in all this. And sorry for my bad english. Thank you guys, in advance.