Hey,
I got the same error as already reported in Issue 9.

I am on Microsoft Windows 11 Pro (Version 10.0.22000 Build 22000), I set up a new conda environment, installed cookiecutter and tried the command cookiecutter https://github.com/at-gmbh/at-python-template.
The commands I executed:
conda create --name cookiecutter-env
conda activate cookiecutter-env
conda install -c anaconda python=3.9.*
conda install -c conda-forge "cookiecutter==1.7.*"
cookiecutter https://github.com/at-gmbh/at-python-template # using always the default option
I also created a new conda environment with a newer version cookiecutter version 2.1.1, but I got the same error.
Here is the file when you run the cookiecutter command with --debug-file: debug.log