Tekkit wont let me use my original Vanilla Server

[Courage86]

So a few weeks ago i started my tekkit server with now problems to be seen or heard. Then came the update for vanilla so i decided to update my vanilla server so my group and I could explore all the new changes but for some reason it keeps saying "Can't reach server". I know you cant have both up at the same time and i even deleted both servers (backing up the tekkit world of course) and re-installing the vanilla just by itself but still cannot reach. i even went so far as to do all the port forwarding over and still nothing. has anyone had this problem before? if so or not please help

:(