Report created in SSRS 2008 is not able to upload in 2008 report server

Question

I have created a report in SSRS 2008 version. Our reporting server is 2008 R2. I'm getting the error given below while uploading the .rdl file to report server. 
The report definition is not valid. Details: The report definition has an invalid target namespace 'http://schemas.microsoft.com/sqlserver/reporting/2010/01/reportdefinition' which cannot be upgraded. 
Then I've checked the code of the solution and it is created in 2008. It is given below:
" Microsoft Visual Studio Solution File, Format Version 10.00 # Visual Studio 2008 ........."
Also, I've checked the code of .rdl file but that made me confused. It shows that the file is created in 2010.
<?xml version="1.0" encoding="utf-8"?>
<Report xmlns:rd="http://schemas.microsoft.com/SQLServer/reporting/reportdesigner" xmlns:cl="http://schemas.microsoft.com/sqlserver/reporting/2010/01/componentdefinition" xmlns="http://schemas.microsoft.com/sqlserver/reporting/2010/01/reportdefinition"> 
Visual studio 2010 is also installed in my system. Also, I have noticed that even if we try to open a report then by default it is showing data tools option.I have tried multiple times to create report in 2008. But, still the same result. Also, I could find
that ,the report will be in 2008 till the creation of data source. The report will be converted to 2010 after creating data set. I have been creating shared dataset and I was getting the above issue.Then I have tried by not creating a shared dataset and
directly creating dataset in the report data and it has been created as 2008 report. I was able to upload this report to report server 2008R2. 
Can any of you help me to find why the report is created in 2010 while creating shared dataset?

Answer 1

I have created a report in SSRS 2008 version. Our reporting server is 2008 R2. .
xmlns="http://schemas.microsoft.com/sqlserver/reporting/2010/01/reportdefinition"> 
Hello Julie,
You mix up Version of Visual Studio, Reporting Services and Report Definition; all those products have Independent Version numbers and are not related to each other.
Important are the Versions of used SSRS and BIDS, the plugin for Visual Studio. By the Version of Report Definiton you have create a Report with BIDS 2008R2 or SSDT = SQL Server Data Tools; see
http://schemas.microsoft.com/sqlserver/reporting/2010/01/reportdefinition/
Are you sure you have SSRS 2008 R2 (in post subject you wrote SSRS
2008)? If it's SSRS 2008 then you really can't deploy the Report to SSRS, you would have to use BIDS 2008 to create the report. Check the Version of SSRS or use "Report Builder 2.0", you can start it directly from "Report Manager"
URL.
Olaf Helper
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