I created groups : coal , iron , gold etc .. i gave each one some permissions like fly.fly , when i check in console to see what commands each group has it shows them , but when i give myself one of the ranks no commands works and it says you do not have acces to that command . What is happening?pls help me fast

Permission nodes are directly related to the plugins which give those abilities. The node fly.fly would have to be from a plugin of some sort in order for it to do anything on the server. As far as I'm aware, fly.fly isn't from a plugin, so no users would be able to fly if you give that node to them.