NoSuchFieldError: materialPureifiedCertusQuartzCrystal (AE2 & Thaumic Energistics)

What the log looks like

java\.lang\.NoSuchFieldError: materialPureifiedCertusQuartzCrystal
cpw\.mods\.fml\.common\.LoaderException: java\.lang\.NoSuchFieldError: materialPureifiedCertusQuartzCrystal

How to fix it

1. Open your Minecraft mods folder and locate the .jar files for both Applied Energistics 2 and Thaumic Energistics.
2. Download the latest matching 1.7.10 releases for both Applied Energistics 2 (such as rv3-beta-6) and Thaumic Energistics from CurseForge so they target the same AE2 API revision.
3. Update any other Applied Energistics 2 addons in your modpack (such as Extra Cells 2 or Wireless Crafting Terminal) to versions built for the same AE2 release channel (rv2 vs rv3).
4. Remove the older .jar files of Applied Energistics 2 and Thaumic Energistics from the mods folder before relaunching the game.

Check your own log