I had the same problem as most of you, this is what i did:
1. Migrate your account by signing in here https://account.mojang.com/login?redirect=https://mojang.com/
2. Log out of both minecraft and technic on their launchers
3. Relog on minecraft first then on technic
It should work now, this worked for me
Hey Creeper can you add my friend hosmo?
Username:hosmo
Reason: He likes tekkit and is my friend, he want to get out of the griefers etc.
he is not experienced in tekkit
will you follow the rules? Yes, Of course
He asked me to put in on because he doesnt have an account on the forums
First I would Like to say HEY CREEPER im glad to see you opened up your own whitelist, we played together on eternia craft xD
|Your Username:|The_Wriddler
|Your reason for joining the server:|I played with you before and i havent been able to find a good server since.
|Are you experienced in Tekkit:|Pretty much yes, still have some stuff to learn though
|Will you follow the rules:|Of course, always have, always will
Hello, i have been on the server for a bit, however, i am continuously being kicked for fly hacks, and i do not believe i am the only one, can you please disable this or fix it so i can get back on? thanks
-The_Wriddler
Your Minecraft username: The_Wriddler
Your age: 14
Your general location in the world (Earth) Florida
Your ideal starting area/biome, and most desired local resource? a mountinous area, and coal
A general description of your ideal playstyle and any other information about you: I hate griefers and i like to team up with people to achieve success in a server
IGN: The_Wriddler
Age: 14
Reason for joining: I want a server with no banned items and no griefers or rule breakers
Have you read the rules: yes, and i agree with them
Tekkit experience: a good amount, been playing a few months
Game Nickname: The_Wriddler
Age: 14
Reason for wanting to join server? I Believe it will be a good server and i hate griefers/rule breakers.
Experienced in tekkit? Pretty much, not in all parts but most.
Do you Swear that you will follow the rules? always will