r/LaTeX

How would I go about trying to recreate this

For some reason Polish breaks biblatex. I have simple test article

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}

\usepackage[style=apa, sorting=none]{biblatex}
\addbibresource{sample.bib}

\begin{document}

	This should always work (\cite{einstein})

\printbibliography

\end{document}

This works and everything is fine, but when I change \usepackage[english]{babel} to polish it doesn't compile and I get errors

Undefined control sequence. This should always work (\cite{einstein})
Undefined control sequence.

I tried with German, Spanish and even Russian and it worked but Polish doesn't, why? How to fix? I use TeXstudio

Working on building a fully accessible LaTeX thesis template (WCAG 2.1 AA, ADA Title II, PDF/UA-1) for a worldwide reputed university.

Three help:

• Does any university already have a thesis template that meets these standards? Would love to see how they handled tagging, structure, and figure alt text.

• Recommendations on docs/resources to read before I start the build? Specifically interested in tagpdf in production use, accessible math (MathML output), and PAC verification workflow.

• is there any verification tool that tells me if the template is following (WCAG 2.1 AA, ADA Title II, PDF/UA-1) or not.

Anything helpful welcome. Thanks.