My R36S won´t start Pokémon Brown (Romhack)

Hey guys, my R36S runs perfectly fine so far, but whenever I try to launch Pokémon Brown it just shows the loading screen twice and then takes me back to the main menu. Also, the file somehow is shown as ".- Pokémon Brown". I did try to change the core in the game meta settings, but nothing worked so far. Does anyone have a solution for this?