Modpack Not Working on Some Computers Only

[Gman108]

Hello,

I made a custom modpack to use with a couple friends on a personal server that we are creating. While it runs perfectly on some computers, on others it doesn't even make it the Mojang screen before crashing. I'm not sure what is wrong with it; could someone please help me? Here is the crash report: http://pastebin.com/qyFdzwvs

Here is a link to the modpack itself: http://www.technicpack.net/modpack/idaka-dictator.635744

Thank you!
Gman108

[planetguy]

Your modpack requires classes new in Java 7. Have the people who are crashing update their Java.