Have you seen the error “word experienced an error trying to open the file” when using Outlook 2016? This is because the Office trust settings are preventing you from opening untrusted files. Follow these steps to work around the issue –
Close Outlook
Open Word
Go to File and Options
Go to Trust settings, and advanced settings
Go to Protected View and uncheck the box to Allow Outlook to open attachments
Also go to Trusted locations and add C:\ (check the box to also allow sub folders)
Open Outlook and try to re-open your attachment