Trying to process a sales payment - account set to sales. When entering received payment opens new page which account when clicking the drop down box is empty and clicking next does nothing.
How did you receive payment? In cash or bank deposit? Create an account under Cash accounts or Bank accounts tab.
In future it will be more obvious, for now, just remember the dropdown box enumerates list of bank/cash accounts. If you haven’t created any, the box will contain no option.