The New Sales Invoice form is showing the message: “Missing Fields; Mandatory fields required in table Items, Row 1; Income Account” and jumps to “Items”. 
It seems to be something that is not configured right.
I feel like running in a circle not seeing the elephant in front of me. ERPNext was installed 3 days ago with the SKR04 standard template. 
Stay healthy and if I can help, just send me a message.
Open your item from item list, go to Sales, Purchase, Accounting Defaults section.
Add your company and set default income account.
Else, open the row from item table of Sales Invoice and fill this portion.
@rtdany10 You solved the issue! 
Can this solution be copied over all items? Or is it something that always has to be done in Item creation?
I’m not sure what you meant by
Your solution requires a change in an individual item. The sales invoice process only works, when all items in the item list are changed this way.
Usually, if you have set the default income account, this error wouldn’t happen.
Open your company from company list and go to Accounts Settings and set default income account there,
Hi!
I encountered the same problem, and this solution’s perfect!
Do you know if it’s possible to set the income account for an item group instead of an item?
Thanks!
