Answer:
The working directory is a local path where the data of the currently opened structure are temporarily handled and saved. It consists of the first letters of the file. Only ASCII characters may be used.
Non-ASCII characters are, for example, "ä", "ö", and "ß".
To avoid this problem, replace the special characters in the file name with ASCII characters, such as "ae" and "ss" instead of "ä" and "ß". When you open the file again, the message will not appear.
