Data source error: The 'stageid' column does not exist in the rowset.

Have a look in the Query Editor and see whether StageID is being used as part of your steps in getting the data from the Source into whatever tables you are using for your reports.  Perhaps StageID used to exist and was being removed by "Remove Columns" but now its no longer in your data source.  Maybe StageID was being created as part of this process, but was no longer needed so the step was removed but a later step is referring to it.