Astral Trekker

Didn't work for me with tekkit lite..the newest version of Optifine wasn't compatible with the version of Forge the launcher gives you, so I had to update Forge.

Have you tried updating your Forge version? I had trouble using Optifine with the default version 6.6.2.516 the Technic Launcher gives you, try updating Forge above version 6.6.2.518 and it might work..also re-install Optifine after you update Forge.

Oh and also after you install Forge, you should re-isntall Optifine because they both use some of the same class files.

The fix is pretty simple. You need to upgrade your Forge version, I think Tekkit Lite gives you version 6.6.2.516 by default, I believe..Download a version above 6.6.2.518 and everything should work.