2020-04-27-7.log

The game crashes while loading the world

Your whole install appears to be corrupted in some way. Have you tried reinstalling the pack?

It seems like you tried to install the custom jars for GTCE and SoG but they didn't download properly. Minecraft can't read them for some reason. Please re-download the jars from the links in Installing Unofficial Fixes. The two links in the paragraph talking about them are what you want.

Yeah looking at a working log it seems the missing signatures are nothing to worry about, so your only issue is likely with the fixes Exa mentioned.

I'm also seeing something far later in your log about AE2 trying to cast an energy cell into a crafting unit, which suggests that maybe you have an energy cell next to a crafting CPU multiblock? Though I don't know why that would cause a crash.

I don't have an energy cell, I would try re-installing the game and jars.

The world is corrupted.

In that case all I can suggest is to restore from a backup. Corruption only happens under particular circumstances like killing the process while the save is being written to, or a full/failing drive.