User is trying to create a vendor bill, but cannot save it and gets an error that a memo is required.
This can happen if the project against which you are adding service or expense items on the vendor bill has the project rules Memo is required for time entry or Memo is required for expense entry turned on. These rules prevent you from creating time or expense entries without a memo. You need to enter the memos for the service or expense items by exposing the Memo column (More > Show/Hide Columns > Memo) on the vendor bill in order to save it. Otherwise, to save the vendor bill without entering memos, you need to remove these rules for the project from the Projects > General > Assignment screen. Check the Core Help for more on project rules.