So, you load in, and the game immediately freezes while music keeps playing?
If you're saved in the wild area, it's likely it's a software freeze due to den data, as I've had a similar issue.
Should be able to open PKHex or a similar raid editor and set the dentype number to 0 for all raids, and save and retry with the edited save. I did this on my save and was able to obtain new raid data and my save was fixed.