I am using D365 online. If I write a report using report wizard, download and add to project in Visual Studio 2015, on opening I get an error'Unknown report version 9.0'. Using the most recent report authoring extension as in https://technet.microsoft.com/en-gb/library/hh699675.aspx which
also checks for updates. Any ideas?
I think that the the report version is too old. Can you try this solution ?
Download "SQL Server 2012 Express with Advanced Service" from MSDN and installed the SSRS report editing tool and then used those to open and save reports. This upgraded the .rdl files with the good report schema.
I wrote a blog post on this: the Report Authoring Extension is only supported on VS 2012 and 2017. I found that if I download the report from D365 Online, open the RDL in a BIDS project under VS 2012 and save it, then I can open it using VS 2017.