My CSS for Project M 3.5 is freezing now that I tried to add new stages into it. I followed the steps detailed in Arko's Project M Modding Tutorial for Adding Stages
https://www.youtube.com/watch?v=xOTvcvrk7mc down to a T. I put in the .rel's and .pac's, went into the game, played the stages, and they worked fine. They had no names, icons, logos, anything (Aside from the default ones).
Once I went back into the Stage Manager and added the icons and names, then the game started to freeze. All of the icons (Except for two, which I just left as the default ones) came with the download link for the stage and were built specifically for PM, so I know they're the right size. Same with the name and previews.
The only thing I can think of that I did differently than normal was use the Stage Manager rather than Brawl Box to add the icons and such.
The Crash involves the CCS freezing a a loud buzz noise, if that helps.