Hi Christian M, I'm Femi and I'd be happy to help you with your question. This issue occurs because of a character limit on creating and saving files in Office products. This issue occurs if the path of the file that you open or save meets the following condition: Microsoft Word, Microsoft PowerPoint, and Microsoft Access: The total length of the path and the file name, including file name extension, exceeds 259 characters. Microsoft Excel: The total length of the path and the file name, including file name extension, exceeds 218 characters. Kindly open the link below for detailed information on steps to take to troubleshoot this challenge. https://learn.microsoft.com/office/troubleshoot/office-suite-issues/error-open-document Kindly let me know if you require additional support.
Best Regards, Femi