# Package doclicense gives error with hyperxmp; PDF is produced

Compiling the following MWE:

\documentclass{article}

\usepackage[
type={CC},
modifier={by-sa},
version={4.0},
lang={spanish}

\usepackage{lipsum,siunitx}

\begin{document}

\lipsum[1-3]

\end{document}


When I compile I get the follwing error:

! Undefined control sequence.
<argument> \hyxmp@dc@lang


However, even with the error, a PDF is produced. How does one get rid of the error? This started happening after my last TeXLive upgrade; current version is 2020.20200925-1 (running on Debian Testing); doclicense is version 2.2.1.dev.

The doclicence package says that it requires hyperxmp. However, your code would not run for me unless I explicitly loaded hyperxmp under v2.2.0 of doclicense. When I updated to v2.2.1 of doclicense the issue went away. (I have v5.4 of hyperxmp.)

\documentclass{article}

\usepackage[
type={CC},
modifier={by-sa},
version={4.0},
lang={spanish}

By loading hyperxmp explicitly, I got the output shown below with v2.2.0 of doclicense:
• Right! I suppose the version I have of doclicense is still "in development", because it says it is v.2.2.1.dev. This works; what I don't understand is why now, I had been working with files using doclicense before without this error. Thanks! – mathbekunkus Oct 7 '20 at 3:51