When trying to save an L. Keeley Opportunity as Closed Won, you will receive the following errors if you are missing the required Sales Tax fields. Follow the below instructions to fix
1. Navigate to the Opportunity you are editing2. Scroll down to the "Performance Type" field and select any non-blank value.
3. Scroll down to the "Construction Type" field and select any non-blank value
4. Scroll down to the "Construction Use" field and select any non-blank value.
5. Once you have a value in all three of those fields, you will be able to save the Opportunity as closed won