Tried to use UseHtmlBasedEngine(true, true), cannot solve the problem.
I am using version 20.4. and SharePoint 2013. I am getting the same error for GetDocumentHtml -> Gethandler.GetPages(filename, options). Hoping for your immediate assistance
Please make sure that you are using GroupDocs.Viewer for .NET version 20.4 in your application. Because v20.4 follows this code example getting HTML representation.
API allows you to load document from different sources. In your case (if you are getting the source document as a stream) you may find load document from stream helpful.
This is okay now thanks God. I found resolution for this through another post here. Adding UseCache = true in the code below solved the issue.
ViewerConfig cfg = new ViewerConfig
StoragePath = _storagePath,
CachePath = _cachePath,
//UseCache = false
UseCache = true
Thank you very much.