You observe error "Cannot save page: PAGE_NUMBER (error:x845) Description: Unknown Error) from TIFF Producer actions (ZyxmlTiff JPEG). In the ZySCAN log ( \\ProgramData\Zylab\ZySCAN\ZyScan.log ) you find following w arning message "WARN Images - Unsupported save format used" and you have Microsoft Internet Explorer 8 installed on the node that runs the TIFF Producer.
In order to OCR the produced TIFF images, eDiscovery Bundle uses a system call to detect the MIME type of the file. The Operating System uses Microsoft Internet Explorer to return files MIME types. However Internet Explorer 8 returns MIME type values that can differ from the generally accepted value for backward compatibility.
You can refer to the "Uploaded MIME Types" section of the following Microsoft MSDN article.
Upgrade Microsoft Internet Explorer to a newer (supported) version via Windows Update.