I need help with the custom songs in NSMBDS. Because I just put 2 songs from Mario and Luigi: Bowser's Inside Story into the game and when I tried playing them in boss fight levels, it doesn't work. all silence. Can someone help me?

I tried on this level: https://ibb.co/nqJKRT58
and this level: https://ibb.co/XxJsr009

(the images are in links)

You need to replace the sseq, sbnk, and swav files with the originals or adapt the sseq to the NSMB soundfont. This is a very common problem when trying to explore the limits of NSMB with music. The truth is, if a piece of music has many complex samples or is very long, the SDAT file gets corrupted. I don't know if it's due to lack of space or something similar, but the solution is to adapt the sseq or create an sbnk file and a swav file with NSMB DS-compatible samples. If this doesn't convince you, you can experiment with the notes in Nitro Studio 2. That's my recommendation. It might seem tedious, but it's always possible.


_________________________
The star project that shows my brilliant mind