The Void Decay mod for 1.7.10 adds new explosives that can destroy all of the blocks in your world. The only way to stop it is to use cleaning explosives.
Download the VoidDecay mod for 1.7.10:
VoidDecay Mod for 1.7.10
Forge for 1.7.10
Locate your Minecraft.jar file.
Open Minecraft.jar using Winrar and delete the META-INF folder
If you haven’t already installed Forge, drag the files from the forge zip file into Minecraft.jar.
Run Minecraft once
Drag the mod .jar file into the .minecraft/mods...