So I'm using SonEd to make a simple level hack experiment for Sonic 2. I got about halfway into finishing the 1st level, so I decided I should test it to make sure it worked properly. I saved the project but when I played it, it hadn't saved my level. It was just normal Sonic 2, nothing was changed at all and I had lost all of my progress. This has happened a bunch of times and I really need help.
What is the name on the ROM file you're testing? If it's not "s2build.bin" or something of the like, then you're likely testing the wrong ROM file.
Are you even using a disassembly? SonLVL or SonED2 are better than SonED. In a disassembly you have to save the level and assemble the ROM later.
I'm using SonEd for now. I have SonEd 2 and SonLVL downloaded on my computer but for some reason I can't get them to work properly. I didn't name the file that. I just came up with a random name off the top of my head and I ended up naming the file "sanic.bin" Staff edit: Don't double-post.
SonED is outdated, and it's more recommended to use SonED2 or SonLVL along with a split disassembly. There are guides over at Sonic Retro for how to set them up: SonED2 SonLVL