I try to setup a content type with a custom template, e.g. a report document.
When I setup advanced settings of the Content Type to use a Word Template (report.doTx) it will accept. But when I try to create a document in the library based on this content type, it will open in Word Online with this error: The document you are trying to open is a template. Would you like to open and edit as a standard document? The same error will occur with the default template.dotx in a library, so it's not my template that has a problem.
When I use a normal document (report.doCx) instead, it will not give me this error. But this seems counterintuitive. The system is asking for a template, but I supply a document? When setting the library to open the Desktop App, there will be no error.
So? What is the expected file type to supply to the template of a Content Type?