When refreshing data extracts from Excel data sources, some measures are reverting into dimensions - and string data types - probably due to NULL values in the first rows the the updated data source.
This causes a whole lot of red exclaimation marks, and view failures. It also causes havoc with automated data refreshes using Tableau Server.
Is there a way of enforcing data types without having to manually fix them up one by one in Tableau desktop after each refresh?
Retrieving data ...