And I guess you installed FBI into the NAND because you were trying to install it to sysnand?
Yes because i can't install on sd card with fbi
Well my friend that's your issue right there...
The NAND is the internal 3DS memory, only system titles and DSiware should ever be installed there, nothing else!
You must install EVERYTHING else to SD.
You must likely have a missing database and that's why you were unable to do it last time around.
So you need to:
1)Delete BBM from the NAND.
2)Create a database.
3)Install all your cias to SD from now on.
Q: I'm getting a "DESCRIPTION_DATABASE_DOES_NOT_EXIST" / "DESCRIPTION_INVALID_DATABASE" error!
A: This shouldn't happen any more, as FBI takes care of initializing the database files for you. However, if it does, you likely haven't installed anything from eShop or other locations before. You will need to go to the "Nintendo 3DS/<id0>/<id1>/dbs/" directory on your SD card and create empty "title.db" and "import.db" files. Then, go to System Settings -> Data Management -> Nintendo 3DS -> Software on your 3DS and let it repair the database files.