Just a follow-up to one I posted some time ago where I always recieved the error below in a certain schema SDXML generation. I finally traced it down to a package with an embedded CHR(05) character that looks very similar to a pipe. Object type filters and then Object Set filters made the detective work pretty easy.
An error occurred while attempting to write the following
objects to the XML file. Some of their properties may not
be present in the file.
STR: Error - An invalid character was found in text content