I red a answer from http://scn.sap.com/thread/2138029 said as below but I can't find properties for rpt file. Where is it?
I also got the error few weeks before. I just did as like below
1. Right click the Rpt file.
2. Choose the properties
3. Changed
a. Build Action as "Content"
b. Copy to Output Directory as "Do not Copy"
c. Put Empty for Custom Tool and Custom Tool Namespace
After did the above steps i deploy my application and then it works fine for me.