First, this question asked in Reddit PayPal Forum.
If you are transferring money or sending money from your PayPal account to another Bank account, then their may be problem in your PayPal. You might have not setup PayPal Cash and PayPal Cash Plus in your PayPal Account.
If you are transferring money from your PayPal account to another PayPal account, then their may be funds shortage in your PayPal Account. Top up your PayPal balance and try Again.
Always, Link your PayPal account with Bank Account.
Don't maintain zero balance account.
Always setup PayPal Cash and PayPal Cash Plus with your PayPal account.