Whenever I try to launch a non minecraft version it doesnt work

whenever I launch a seperate version other than already supplied mine craft versions like 1.8 it says failed to download file

Failed to download file. OptiFine-1.8.9_HD_U_H8.jar
Name: OptiFine-1.8.9_HD_U_H8.jar
URL: https://libraries.minecraft.net/optifine/OptiFine/1.8.9_HD_U_H8/OptiFine-1.8.9_HD_U_H8.jar
Error details: HTTP 404: Not Found
Filename on disk: 8fac-4ddd-3148-f903
Path: C:\Users\Ryan\AppData\Local\Temp\8fac-4ddd-3148-f903
Exists: file

Please tell me why it does this and how to fix