When selecting an existing item on a transaction in QuickBooks desktop, one of the following messages appears:
" cannot be added. QuickBooks cannot add more than one level to the Item list at a time."
"QuickBooks did not find in your list of products and services. Would you like to add it now? If not, go back and select and existing product or service."
"Warning: [Account Name] cannot be added. QuickBooks cannot add more than one level to the Account List at a time."
In earlier versions of QuickBooks desktop, it was possible to create items with spaces at the beginning of the name. In QuickBooks 2013 desktop or later, spaces at the beginning of an item name generate errors when you try to use those items in a transaction. This can also happen if a sub-account has an account number but the parent account does not.
Edit any items or sub items that contain spaces at the beginning of the name.
Edit any parent accounts and check for account numbers: