Distribution Manager does not have sufficient rights to read from the content source folder or to write to the destination ...

1. Distribution Manager does not have sufficient rights to read from the content source folder or to write to the destination folder on the distribution point. In the Configuration Manager console, verify that the site system connection accounts have sufficient privileges to the source and destination folders.
2. The distribution point might not be accessible to Distribution Manager running on the site server. If users are currently accessing the content files on the distribution point, disconnect the users first. If the content distribution point is located on a Windows computer, you can force users to disconnect by clicking on the 'Disconnect users from distribution points' box in the Data Access tab of the Content Properties dialog box.
3. The distribution point does not have enough free disk space to store the content. Verify that there is enough free disk space.
4. The content source folder contains files with long file names and the total length of the path exceeds the maximum length supported by the operating system. Reduce the number of folders defined for the content, shorten the filename, or consider bundling the files using a compression utility.