Please can you provide the workbook with sample data so that we can see the issue?
You need to aggregate values if you're taking it from a different data source, and this gets more complicated if you include LODs as well. So to help us review your issue, please provide us with the workbook.
i cant, i would off...
can you explain a little bit more...
data Source 1: 15 calculations, none are aggregations.... some are LOD,
data Source 2: 6 calculations, none are aggregations, none are LODs
when i bring in the cals from source 2, this is what throws the error... if I add SUM() or ATTR() to these 6, it still errors
When you bring in multiple data sources via the blending method, you need everything to be aggregated in the data source. This is because Tableau uses a group by logic when they bring these data sources together.
With LODs in fact, you can only use them against one dataset. As you have multiple calculated fields across multiple data sources, we'd need to review the workbook file and see what's happening.