i figured out a workaround. first open C:\Users\<insert username here>\AppData\Roaming\.techniclauncher\launcher\technicssp\modpack.yml and change
builds:
7.3.4:
minecraft: 1.4.2
to minecraft: 1.4.4
so it will actually install the modpack. close the launcher completely after it installs.then change 1.4.4 back to 1.4.2. then open the C:\Users\<insert username here>\AppData\Roaming\.techniclauncher\technicssp\minecraft.yml
and change
current: 1.4.4
to current: 1.4.2
close that
download http://assets.minecraft.net/1_4_2/minecraft.jar ( this is from mojang) and replace the minecraft.jar in the C:\Users\<insert username here>\AppData\Roaming\.techniclauncher\technicssp\bin folder
launch and it works.