How much are you trying to send? You can't send less than 0.00000546 BTC (546 satoshis), which is considered a dust amount.
Can you take a screenshot of the last screen before you click "Broadcast"? Specifically, the list of inputs and outputs of the transaction.
Also, make sure you get this right:
Usually this happens because users are confused about the unit of account electrum is using. By default that's mbtc which is 1/1000th of a bitcoin. You can change this via tools > preferences > general tab > base unit option.
