"Opening the .exe does nothing, or flashes a loading icon, or says "checking launcher version" then closes.This is a Java issue. The most common cause is using 32 bit Java. If your Operating system is 64 bit, make sure you update to the latest 64 bit version of Java. Links on www.technicpack.net.
If no matter what you do, the exe just doens't work, go to your .techniclauncher folder and there should be a .jar in there. If not then download
it from www.technicpack.net and use that. Read further up the list for how to determine the bit version of your OS or JAVA."
(the .JAR is there it just does not work)