Running the cppcheck plugin on a report generated with cppcheck 1.63 (current stable version) gives the following error:

[Cppcheck] Starting the cppcheck analysis.
[Cppcheck] Processing 1 files with the pattern 'cppcheck.xml'.
[Cppcheck] Parsing throws exceptions. org.jenkinsci.plugins.cppcheck.model.Error cannot be cast to org.jenkinsci.plugins.cppcheck.model.Results
Build step 'Publish Cppcheck results' changed build result to FAILURE
Build step 'Publish Cppcheck results' marked build as failure

It works fine with cppcheck 1.62