No data when aggregating data sources
I've made a dashboard inside of Data Studio using multiple data sources including Facebook Insights, LinkedIn Company Pages and Instagram Insights.
As you can see in screenshot1 I've made my own data source using blended data (Facebook Insights, LinkedIn Company Pages and Instagram Insights). Now if you look at screenshot2, you can see that I've made a custom field because I want to aggregate all social media followers into one number using the scorecard chart. I've aggregated all data sources like this: sum(x)+sum(y)+sum(z). But as you can see I get an error message saying "No data" and I dont see what I did wrong. Can anyone help me out? Thanks