NEW: TikZ book now 40% off at Amazon.com for a short time.
And: Currently, Packt sells ebooks for $4.99 each if you buy 5 of their over 1000 ebooks. If you choose only a single one, $9.99. How about combining 3 LaTeX books with Python, gnuplot, mathplotlib, Matlab, ChatGPT or other AI books? Epub and PDF. Bundle (3 books, add more for higher discount): https://packt.link/MDH5p
Your problem description remains unclear because your example is still not a MWE. You try to use some definitions for the listings style which are missing in your code (as the error message clearly states). Take a close look at the content of the archive behind the link »Beispielartikel (Quellcode)« on the page you mentioned. The missing style definitions can be found in the file »layout.tex«. Either try to run the compiler on the file called »main.tex« and see what happens or copy the relevant parts to your MWE and then try this one.
Now that the problem is solved, please act as you already have been directed in my last reply. Furthermore it is very appreciated if you react on replies to former requests [1,2,3].
NEW: TikZ book now 40% off at Amazon.com for a short time.
And: Currently, Packt sells ebooks for $4.99 each if you buy 5 of their over 1000 ebooks. If you choose only a single one, $9.99. How about combining 3 LaTeX books with Python, gnuplot, mathplotlib, Matlab, ChatGPT or other AI books? Epub and PDF. Bundle (3 books, add more for higher discount): https://packt.link/MDH5p