File Preview Not Supported for Certain File Types in Jira Service Management Portal (v10.7.4)

[Mikko Taponen]

In the portal view, certain user-uploaded attachments do not open in the preview window. Instead, an error message appears: File type not supported. Types that do not open XLSX, DOCX, PPT, TXT. Files that are working JPEG, PNG, PDF.

So the users cannot preview common document formats directly in the portal. Files can still be downloaded and opened locally without issues.  So is there any another way to preview the file, user can of course download it? 

This subject may have been unresolved for years, if I have understand what I have read.