Diagnosis
You want to access an original for a document master record. Theoriginal is in the file system. When you tried to access the original,no SAP-GUI was active. Therefore, an attempt is made to read the filefrom the application computer.
The file is not accessible under this path on the application computer.

Procedure
If you want to distribute the document nevertheless, you can check theoriginal into the SAP database, a vault, or an archive. Then you canrestart the distribution.