I have two tables from two different SQL servers and I wish to append one table to another. Everything worked fine until I uploaded the report and tried to refresh. Then it failed and said "There was an error in the data gateway". I use an enterprise gateway. I have tried setting all data sources' privacy level to "None" and it still didn't work. Pretty sure the issue came from appending the queries because if I deleted the step "Append Queries" and reuploaded the report, the data refresh worked fine.
Can anyone help? Thanks!