Viewer error when attempting to export to PST (bitness error)

Viewer throws an error when attemping to export to PST.

First check the log for a more detailed error message

Open File Explorer and type %APPDATA% into the address bar, then drill down to C:\Users\[username]\AppData\Roaming\Gwava\Retain Publisher\

Open the Viewer log and find the error.

2016-09-21 13:06:14,500 [6] ERROR Publisher - An error occurred during exporting to PST. For additional information see error details and Viewer.ExportToPst.log file.
System.Exception: Cannot determine bitness of installed Microsoft Outlook. Registry key 'SOFTWARE\Microsoft\Office\16.0\Outlook' not found.
at GW.Export.Pst.Utilities.MapiUtilities.GetOutlookBitness()
at GW.Export.Pst.Utilities.MapiUtilities.DetermineMapiBitness()
at GW.Viewer.Export.ExportService.StartPstExportServiceProcess(String exportSessionId, ILog log)
at GW.Viewer.Export.ExportService.c__DisplayClass3.b__1(Object obj, DoWorkEventArgs evt)

In this case we find the error being "Cannot determine bitness of installed Microsoft Outlook. Registry key 'SOFTWARE\Microsoft\Office\16.0\Outlook' not found."

You can reinstall Outlook or follow the advice in this stackoverflow article to add the proper REG_SZ key.
 

This article was originally published in the GWAVA knowledgebase as article ID 2862.