I added version 1.0.2 to my personal mod pack and I am getting a rather weird 'java.lang.NoClassDefFoundError: net/minecraft/client/renderer/EntityRenderer' crash.

The crash occurs while loading in to minecraft, my pack is generally well behaved, and I have not seen a crash like this before.

I cleared my logs files/folders then re-launched the pack to create clean logs, in the hope that it helps you resolve the issue.
Mod list should be in the log files.

crash-2016-04-15_21.41.18-client.txt
fml-client-latest.txt
fml-junk-earlystartup.txt
latest.txt

For a quick solution, add a "Z" to the beginning to the Fairy Lights jar name.
fairylights-1.4.0-1.7.10.jar →Zfairylights-1.4.0-1.7.10.jar
This makes Fairy Lights load after The Betweenlands