Overview
Preview for Office documents (e.g. MS Word, Excel, PowerPoint etc.) in M-Files Desktop client views always uses Windows previewer as default, as it more efficient than using M-Files own preview handler. Sometimes you can face trouble when previewing Office document (Word, Excel.) in M-Files views which can be raised by issue with Office preview handler itself. You can check Windows previewing by copying an Office document (e.g. .docx) file in your local drive and select preview pane from Windows Explorer view panel. If preview is not working in there, then we suggest you use the below workaround. This error is shown usually in Preview Window:
Error: Preview of the file "<file_name>" failed. Unspecified error.
Solution
In M-Files Web and M-Files Desktop client (search result preview), M-Files always uses its integrated previewer by converting the Office files to PDF, hence preview is rendered without any error. You can change this default functionality of preview in M-Files views by setting the following registry key which forces file conversion to PDF always prior previewing.
Key Location: HKEY LOCAL MACHINE\SOFTWARE\Motive\M-Files\<M-Files version>\Client\Common\NonVaultSpecifics\PreviewHandlers\<extension with dot>
Value Name: UseConvertedViewerFile
Value Data: 1 (always use viewer file conversion (e.g., conversion to PDF file))
Value Type: REG_DWORD (DWORD 32-bit Value)
If you want to target this setting for all filetypes, the key is set without the extension:
Key Location: HKEY LOCAL MACHINE\SOFTWARE\Motive\M-Files\<M-Files version>\Client\Common\NonVaultSpecifics\PreviewHandlers\
** Please note that using this registry setting might reduce the optimal performance for document preview. It might require restarting MFClient service for having this setting in effect.
