Esock

Yo man, I'm having a similar problem. My SSP crashed after I entered in creative mode and set out some redstone wireless receivers and transmitters. After I set them down, I picked one back up using the "pick block" feature and the game crashed after saying "shutting down internal server" or something of the sort. trying to move my character in MC Edit and see if it has similar results to you. EDIT: Tried moving a great distance away. Still announces "shutting down internal server". I wonder if it has to do with inventory. I'm going to try what you tried; deleting all panels in the area, and see if that works out in my favor. EDIT: Did not help at all. Looking for any suggestions... :/

Yo, EarthApocalyto and andrewdonshik, it worked! Thanks so much!! Finally after many tries of attempting to install it like a regular mod this way worked indefinitely. +1 internetz to you both. Thanks again!

*sigh* ...I'm on a Mac. ".jar" files must be unarchived or unzipped to access the files on OS X. I've tried it by replacing all items in modpack.jar as well as doing that AND deleting the META-INF folder. For now, I guess I'm stuck until someone else solves it because I am completely out of ideas.

Is your computer OS running Windows or Macintosh?

How can one access "modpack.jar" to add the contents of Optifine without unarchiving the .jar contents..? O-o

I'm on a Mac and I've tried just about everything I know. I try installing it in the unarchived "modpack" folder, compressing the folder and renaming it to "modpack.jar"; all mods become disabled and no Optifine shows up. Tried installing it to the unarchived "minecraft" folder; game won't even start. I'm a bit frustrated from wondering why this isn't working at all like it's supposed to. I have the latest version of Optifine. I've tried with 1.4.6 HD U A3 and HD U B2 with no result. I have the latest version of Tekkit Launcher and everything. Frustration.