I installed SQL Server Express Advanced services 2014 version and SSDT 2015 tools.
I built a report using Visual Studio project and tried to publish in SSRS link. I changed the "TargetServerVersion" from SQL Server 2016 or later to SQL Server 2008 R2, 2012 or 2014 but still it gives me an error "The definition of this report is not valid or supported by this version of Reporting Services. The report definition may have been created with a later version of Reporting Services, or contain content that is not well-formed or not valid based on Reporting Services schemas. Details: There are multiple root elements. Line 2, position 16638. (rsInvalidReportDefinition) Get Online Help".
Can someone please help