I did a bit of searching and found this issue page on electrum's github repo:
https://github.com/spesmilo/electrum/issues/3427If you refer to comments
https://github.com/spesmilo/electrum/issues/3427#issuecomment-350651693 and
https://github.com/spesmilo/electrum/issues/3427#issuecomment-352871726 it seems to relate to the users attempting to send Bitcoins to an altcoin address. Ensure that you are sending Bitcoins from electrum to a Bitcoin address on Binance. Are you sure you are already doing that and no additional characters or spaces are in the address that you've pasted into electrum while sending?
Basically you send BTC from electrum to Binance's BTC wallet address (your BTC address on Binance) and from there on exchange it for other cryptocurrencies, if that's what you're attempting to do.