Error when writing file

What causes this issue?

The content of the document is saved in a file during export.
An error occuring in the writing to this file.

System Response

The export was not carried out.

How to fix this error?

Please check the file. It may be write protected. It is also possible
that the file size determined when the file was imported into SAPoffice
differs from the actual file size. If this is the case, the file is
destroyed and the file must be imported again.

Error message extract from SAP system. Copyright SAP SE.