I'm upgrading the GroupDocs version used in my app fro 2.17 to 2.19. With 2.17 all documents I've tried preview properly. With 2.19 all documents begin to render. I see the "Loading your content" message. The display is then replaced with "This document is in a format which cannot be viewed by the previewer." I see files created in the viewer cache.
My code is unchanged other than copying the handler definition from the updated GroupDocs documentation. I use the Stream method of the ClientHelper object to provide content to the viewer.
Are there code changes I need to make to be compatible with 2.19?