The error message "Wrong content node response type" and other report failures can be caused by invalid applied filters or a cycle that try to select an invalid value for the field (a value that doesn't exist in the field).
Note: By default, 'verify filter' is enforced programatically in NPrinting 17.x.x.x meaning that if a filter produces empty values in a chart, a report will not be produced and the error you will see is 'Wrong Content Node Type error'.
Your source contain the Year field that contains the values 2012, 2013 and 2014 but you added a filter with Year = 2015 to the report that results in an empty data set.
You added to the report the filter Year = 2014 and the Country field into the Levels node. Remember that adding a field in the Levels node is like a filter. When the report is created it is possible that a value of Country has an empty data set for the year selected. For example, there are not sales in Italy in 2014. This generates the error.
End result: NPrinting may deliver a message to the end user as follows (assuming email is enabled)
"Some errors occurred during report generation
Number of reports not generated: 1"