When I load the mod-pack up the launcher shows this error:

Failed to download file, the file contents differ from what was expected.
Name: jna-4.4.0.jar
URL: https://libraries.minecraft.net/net/java/dev/jna/jna/4.4.0/jna-4.4.0.jar
Filename on disk: jna-4.4.0.jar
Path: C:\Users\nikol\Twitch\Minecraft\Install\libraries\net\java\dev\jna\jna\4.4.0\jna-4.4.0.jar
Exists: File

I was wondering if I have to download something else or if I have to restart my computer. Here is also a screenshot:

What launcher are you using for this? This does not seem like any of the officially supported launchers for ATM-3