Unfortunately, I am neither able to save data in my working directory nor loading the data from it.

Where is your data stored? On what kind of media (a file, a database, etc)? If it is a file, what kind of file (csv, xlsx, txt, etc)?

Ideally, to help us help you, you should prepare a reproducible example (reprex) illustrating your issue. Please have a look at this guide, to see how to create one: