SSRS 2016 SP2 no longer respects text/html MIMEType
An HTML file uploaded to SSRS 2016 SP1 would be identified as mimetype text/html. From the Report Manager portal you could click the link and it would be rendered in a browser window.
After installing 2016 sp2 the mime type for the exact same file is now application/octet-stream. When clicking the link for this file from report manager, it prompts for download instead of opening in a browser window.
This occurs in I.E, Edge, FF and Chrome.
The Use case is uploading an HTML file to include a link/redirect to our data dictionary website to keep our users inside of the report manager portal instead of requiring them to have a bookmark, shortcut etc.
Dan Stoeberl commented
I'm not sure if this is supported but: in the ReportServer database, update the dbo.ConfigurationInfo table where [Name] = 'TrustedFileFormat', and append ", html" to the current value. This appears to control 1) whether the mime type is set when the file is uploaded and 2) whether SSRS will "render" the file or just make the browser download it.
After you update the value, you can re-upload your files or make further updates into dbo.Catalog.MimeType to set them to text/html. Then they'll display in-browser. Tested on SSRS 2017.
This has been broken for a long time - is there no resolution in the works?
I have the same issue and need a solution urgently!
Luke Loeffler commented
Additional Information: This is on a native mode SSRS server.
https://docs.microsoft.com/en-us/sql/reporting-services/reports/upload-a-file-or-report-report-manager?view=sql-server-2016 notes that "Resources are not processed by a report server, but can be viewed in the web portal if the report server supports the MIME type of the file."
Was the text/html MIME type removed from SSRS in service pack 2?