So I am not very good with computers and do not know a programming language or anything, so please bear with me and I will describe the problem as best as I can. My little brother (6 years old) has downloaded multiple mods with the help of our neighbor. I don't play Minecraft all that often, but because I play vanilla more often than he does, I pointed out to him this morning that with 1.8.3 or whatever, you had the option of customizing what biomes would appear in his world etc.. He tried it out, and then logged back out to play on his new world with his mods. He told me the button on the main screen that says "mods" was not showing up. I took a look and confirmed this. I thought maybe he was just in the wrong profile. That is when I saw that he has accidentally (supposedly) created approximately 100 or more profiles. For example he has Forge, (default), forge, one with his initials, plus Copy of Forge, Copy of Forge __, and Copy of Copy of Forge. To give you an idea of exactly how many he has created, one of the profiles says "Copy of Copy of Copy of Copy of Copy of Copy of Forge_______________". Apparently he made a new profile every time he wanted to switch versions, instead of editing his old ones. Furthermore, I experimented and found that every profile I tried would load version 1.8 and up of vanilla, but would crash when loading any version with forge in the name or version 1.7 etc..
To recap, my little brother cannot access his mods because it would appear he can only play the most recent vanilla versions without crashing. He has downloaded many mods (approximately 18) and has made a heck of a lot of profiles. It should be noted that, I have only one mod and three profiles, and I was able to switch between vanilla and my pixelmon mod without any issues.
Please forgive me, I think I can find the most recent logs in the minecraft folder, but I am not certain how I am supposed to display that information (not sure how to use pastebin etc.). Thank you very much.