* In pypsa-eur, there are several files, which must be changed, when changing the config. To make sure, everything is updated to your change, delete all files in networks, resources and results.
***When executing pypsa-eur, I get an error because of a package.**
* There might be a problem with the package itself or the package has been updated and it doesn't work with pypsa-eur, yet. E.g. there is a known issue with ipopt which throws the error message *"Could not locate the 'ipopt' executable, which is required for solver ipopt"* (22.12.2020, https://github.com/conda-forge/ipopt-feedstock/issues/55). To solve this you should remove the current package version (e.g. `conda remove ipopt`) and install an older version that is known to work (e.g. `conda install -c conda-forge ipopt=3.11.1`).
***When executing PyPSA_to_Backbone I get the follwing message: "ImportError: No module named pandas".**
* make sure that correct interpreter is active (pypsa-eur interpreter path on the bottom left in Visual Studio Code (e.g. “Python 3.7.7 64-bit (‘pypsa-eur’: conda)”))
