Thanks guys for the help. I managed to get it to work, although not sure what is was!

Hi, I am new to Bitcoin and wallets but manged to send bitcoin to my Electrum wallet with no problem. But when using it to send a payment, when I click the 'Pay' button a popup window says,  Error - No Output.

I have no idea what this mean and have searched for answer but found nothing. The address is correct and amount.

Anyone know what's causing this? Thanks