On one of our Dell Boomi projects we had a simple task which was to create an XML profile by importing an XSD file that was generated using BizTalk‘s schema generator. While this task seemed trivial at the time, when importing the file that was provided the following error was generated: “Error Occurred: Error on line 1: Content is not allowed in prolog.”
We initially tried looking at the XSD file to see if there were any extra characters at the top of my XSD file and unfortunately could not find any flaws with the contents of the file itself. The next step was to manually create a sample XSD file using BizTalk to test if the error was being caused by the fact that BizTalk was used or if it really was something in the file that was missing.
The sample file that was created ended up having the same error when importing it into Dell Boomi. After some trial and error we were able to work around this error by simply copying and pasting the contents of the XSD into a newly created empty file.
While copying and pasting the contents into a new file allowed us to continue our work and move on further tasks it did not provide a sufficient answer as to why the error occurred in the first place and why copying and pasting worked. After some more research we discovered that the BizTalk generated XSD file actually had an encoding of UCS-2 LE BOM by opening the file up in Notepad ++.
When copying the contents of that file into a new file we noticed that the encoding then became UTF-8. By default Boomi accepts XSD’s to be imported using the UTF-8 format and that is why copying and pasting the contents of the XSD file into another file fixed the above error. So by changing the encoding of a BizTalk generated schema to have an encoding of UTF-8 you can successfully import the schema file and avoid getting the Content is not allowed in prolog error.