I've followed multiple tutorials on increasing the fee in electrum. The message I get every time I try to save it is:

Transaction could not be saved.
It conflicts with current history.

Whatever I do, I can't change the fee. It has been stuck for 24 hours now, way too far from the top and will probably stay like that until I figure something out. Has anyone experienced this with electrum? I have no idea what to do. I've read the thread on stuck transactions, did what it said and again, same error.