I have to highly recommend the following blog article that talks about the upgrade of 10g BI Publisher reports to 11g.
Kan explains the process in detailed steps and I followed his steps to perform the upgrade. The upgrade was successful as he showed in the last picture of publisher reports upgrade section. I have seen my old 10g publisher reports folder showing up. But when I went under my report folders, I tried to open my reports xdo file, it gave me an error below:
The report cannot be rended because of an error,please contact the administrator.
It looked like my report xdo file is not associated with the correct data model file.So then I tried to edit my vat_report report and I saw that after automatic upgrade, my vat_report report was set with the default data model : vat_report.xdm which doesn’t exsit on my data model list. In the presentation layer, the actual data model is called vat_report. Match the correct model by clicking button.
Click View Report to check if you still have the error above and click save to enable the change.
Note: There are file structure changes for BI Publisher upgrade. The original .xdo now is split into two components – .xdm and .xdo as illustrated:(The following picture is borrowed from my other favorite blog: http://howtobi.wordpress.com/2011/01/14/upgrading-obiee-10g-content-to-11g/)