My friend made a mod pack to play with the friend group, and my game keeps crashing.

[henkick]

Hello, i come to you all with a dire need for help. currently I've been trying to get this mod pack to work for the past couple of days and it keeps crashing with this error message, "java.lang.IllegalArgumentException: Found uninitialized runtime mappings!".  I've tried redownloading the mod pack, reset the launcher and Minecraft, added and taken away ram, and trying messing with different cpu settings to see if it was a loading time issue. I don't know what else to do, and this is about the extent of my knowledge. 

 

any help is greatly appreciated, thank you.

[Paint_Ninja]

Please provide a link to your debug.log on https://pastebin.com