I am only able to run Tekkit Classic (indeed any mod pack that I've tried) with Java 32. Upon trying various versions of Java 64, I get the error message "Java(TM) Platform SE binary has stopped working." Been unable to find a solution to this problem so far. I've attached the most recent log from the Technic Launcher.
Running on Windows 7
64 bit OS
8GB RAM
techniclauncher_2017-03-16.log