Please see if the following is applicable:
XML Publisher Report Errors Out With "NumberFormatException" (Doc ID 465193.1)
Otherwise open your data definition and template and ensure the formatting on XXAPR005_RPTA is valid.
Please review and check if you have all recommended patches applied:
Overview of Available Patches for Oracle XML Publisher embedded in the Oracle E-Business Suite (Doc ID 1138602.1)
Was the error due to the parameter change from Program Name to the Program ID for the report XML Publisher Report Publisher?
Problem lies in the code inside the rdf file. The after trigger call for the concurrent program has wrong parameter after the upgrade.