Problem whit starting minecraft forge 1..8.9

[LilacFrappuccino]

Whenever i try to open minecraft forge 1.8.9 it keeps telling me this 

Failed to download file, the file contents differ from what was expected.
Name: jopt-simple-4.6.jar
URL: https://libraries.minecraft.net/net/sf/jopt-simple/jopt-simple/4.6/jopt-simple-4.6.jar
Filename on disk: jopt-simple-4.6.jar
Path: C:\Users\User\AppData\Roaming\.minecraft\libraries\net\sf\jopt-simple\jopt-simple\4.6\jopt-simple-4.6.jar
Exists: File

sorry for the troble but since this appeard i also can not open any other versions of forge(also english is not my first language sorry for any misspelling)