Log or screenshot please.It is in the same folder
Wer do i find the button i dont understand^ press "prt sc" (print screen) button, usually somewhere above your page up/down and delete buttons, then go to paint and just paste the picture there.
Open Paint
ANSWER ME!!!What server are you trying to run?
I don't think any of the jar files are called ftbserver.jar.
You need to use [modpack]_server.jar