I've just been working on my own modpack which has 107 forge mods in right now. But if I open the control panel my game completely crashes. Just so you know, I have like 0 experience with putting modpacks together and API's and stuff...This is the crash report: https://pastebin.com/qQWsMVGp
The modpack itself thinks that this might be the problem:
Try disabling the mod Railcraft and see how it works out.
Proud creator of Ultimate Compression: https://minecraft.curseforge.com/projects/ultimate-compression?gameCategorySlug=mc-mods&projectID=304462
I removed railcraft, and mods that gave the same error afterwards. It still doesn't work.