Alana

"Try deleting the tekkit folder in %appdata% and re-downloading it?" - Drushaii I saw this on the video you posted and i tried it.It worked for me.You should try it to.You will lose your worlds and servers though.Just keep that in mind.

Im having the same problem but not just with tekkit classic.It happens with tekkit,Voxel,Hexxit,Tekkit lite, big dig, and the yogbox.