Did you get this error message when you tried to run a report?
There are a few things that could be causing the error you experienced in the reporting tool. My suggestion is that you run through these in this order to find the problem. Some of these will keep you from exporting a data set while others will not cause problems until you try to run a report using a data set that has the problem.
Having two or more columns in a data set with the same name. To solve this, re-label the question in the process(es) where it appears or use the "combine" feature to re-label the column in the data set itself. You can even use the combine column to rename a column if you have only selected one column to combine. Learn how to COMBINE/RENAME by clicking HERE.
Having one or more special characters (e.g. anything other than a number or letter) in a column name. To solve this, re-label the question in the process(s) where it appears or use the combine/rename feature.
Having a column name that starts with a number. To solve this, re-label the question in the process(s) where it appears or use the combine feature. Note that you can add an underscore character ( _ ) in front of the number to solve the problem.