RIXML validation

Tools designed to process valid RIXMLs can misbehave when provided with invalid file; they can either ignore the non-compliant parts, or refuse to process the document entirely. Therefore to ensure correct processing you should always use valid RIXML files.

RIXML.org provides a description of their format in XSD files; links can be found on RIXML specification page (look for RIXML schema); there are quite a few tools that can be used to verify if a document is correct according to XSD.

I found XMLLint quite useful in troubleshooting RIXML problems; it is a command-line tool that can point you to problems encountered when validating the XML document. In order to use it you need to download all 3 schema files, and then run the following command:
$ xmllint my.rixml --schema RIXML-2_4.xsd --noout

my.rixml:47: element Abstract: Schemas validity error : Element '{http://www.rixml.org/2013/2/RIXML}Abstract': This element is not expected. Expected is ( {http://www.rixml.org/2013/2/RIXML}TitleFormatted ).
my.rixml fails to validate

Well, I'm surprised; according to documentation, TitleFormatted is not a required element, but XSD disagrees.
Anyway. Number 47 in the message is the number of the line where the problem was found. After adding TitleFormatted in line 47, the tool produced only one line:

my.rixml validates

XMLLint is freely available for download; it works under Linux, Windows, and a number of other platforms.