Editing Existing Report

I have a report which uses 4 joined tables from SQL Server. I noticed that there is a column missing from the report. But when I try to add the column onto the report, it removes a different column. When I add that column back onto the report, it adds it twice.

I've tried a few different options now, but I can either have the report without the column, or have it twice.

If I save the report with the duplicate column, then the report doesn't load and shows this error:

Input to resolve-joins-in-mbql-query does not match schema: e[0;33m [(named {:fields (named (not ("distinct" a-clojure.lang.PersistentVector)) "Distinct, non-empty sequence of Field clauses")} query)] e[0m

The fields have the same name right?