There was an error setting up the mapping. DTD is prohibited in this XML document.

In SSIS when we will create task where data source is XML source and we are using inline schema  

We may get an error message like:

There was an error setting up the mapping. DTD is prohibited in this XML document.

Cause: Your XML file also contains DTD (Document Type Definition).  

Solution: SSIS doesn't support DTD in XML file. So remove the all DTD from your XML file.