To successfully "repack" a database, the editor must follow a linear sequence of operations.
Cause: You edited while the game was running in the background. Fix: Force-close FIFA 16, clear app data (not cache) or restart your phone before copying the new DB.
The term "repack" in the context of mobile gaming generally refers to the extraction, modification, and re-archiving of game asset bundles. For FIFA 16 Mobile, database editing is sought after by the modding community to update rosters (squads), adjust player potentials, modify league structures, or correct licensing anomalies. Unlike the PC version, which utilizes discrete .big or .db files accessible via tools like Creation Master, the mobile iteration relies on Unity-based asset bundles or proprietary binary formats, presenting a steeper barrier to entry for editors.
Run DB_Editor_FIFA16_Repack.exe (as administrator to avoid saving errors).
Click "Open Database" and select the fifa_ng_db.db file (for career/offline mode) or fifa_ng_db_market.db (for Ultimate Team/online).