If the TEI parser has to parse a file with namespaces more than once (or, presumably, a file without namespaces after a file with), it will break with an error like this:
XPath error : Invalid expression
//tei:tei:listWit/tei:tei:witness
^ at /opt/local/lib/perl5/site_perl/5.16.1/Text/Tradition/Parser/TEI.pm line 128.
If the TEI parser has to parse a file with namespaces more than once (or, presumably, a file without namespaces after a file with), it will break with an error like this: