Submit of sales invoice

Can anyone help me please,actually i could not submit the sales invoice,this message is displayed

i have input sales of hardware as income account in the accounting details

Hello @trishty_thakoor
I think this error is due to some wrong configuration.
If it is a Sales Invoice it should be associated with a Customer and not Supplier as seen in your screenshot.
The accounting entry for Sales Invoice is Dr to Debtor A/C and Cr to Income/Sales Account.
For some configuration, your Sales Invoice is Debiting a Payable account (which should be a Receivable Account) with an association to a Customer and not Supplier as seen in your screenshot.

Please revisit your configurations to find out what is the cause of error.

Our query is on deferred revenue,suppose we have a maintenance invoice for period July 2019-June 2020.Client already paid in July 2019 and August 2019 to June 2020 is advance payment,so we must account the advance payment in payable account ,not receivable.Kindly advice while selecting the advance payment on deferred revenue.
Do inform us why i am not able to submit the sales invoice as this message is displayed.