Screenshot of problem
The only 3 mods I ever had on my Forge client are Skyblock Addons, Optifine and DisCraft. I decided to delete Discraft from my mod files, then after that, I couldn't open my Forge client. I tried opening the latest, recommended and even 1890 version, but the results are the same.
Yes, I've read the Rules and EAQ post and tried to find anything related to my problem by reading the Common Problems and Solutions section, but I've never heard of MCPatcher til now.