This occurs because the price levels are setup incorrectly for a given task/category. There is no Price Level 1 setup, but there are 2, 3 etc. This typically occurs if the Level 1 Price Level has been deleted from the pricebook, and was recreated (or not).
The Price Levels will need to be deleted and recreated allowing for a Price Level 1 to be established.
If you require further assistance on this topic, please reach out to SuccessWare21’s support team -