I've only seen errors similar to that when a Sales or Purchase Order is created for an Inventory Item, then that item is changed from an Inventory to a Service Item in the inventory module, before an invoice is created.

Or, possibly in multi-user mode an inventory item was set up to be created during invoice / order entry, while at the same time another user added, deleted, or modified that item.

But I've never seen that exact message, it sounds like something has more or less crashed.