When the Nunit plugin tries to read the test result xml file, it gives the below error.

Results (nunit3) saved as TestResult.xml
Recording NUnit tests results
ERROR: Step ‘Publish NUnit test result report’ aborted due to exception:
java.io.IOException: Could not transform the NUnit report. Please report this issue to the plugin author
at hudson.plugins.nunit.NUnitArchiver.invoke(NUnitArchiver.java:71)
at hudson.plugins.nunit.NUnitArchiver.invoke(NUnitArchiver.java:29)
at hudson.FilePath.act(FilePath.java:1018)
at hudson.FilePath.act(FilePath.java:996)
at hudson.plugins.nunit.NUnitPublisher.perform(NUnitPublisher.java:153)
at hudson.tasks.BuildStepMonitor$1.perform(BuildStepMonitor.java:20)
at hudson.model.AbstractBuild$AbstractBuildExecution.perform(AbstractBuild.java:779)
at hudson.model.AbstractBuild$AbstractBuildExecution.performAllBuildSteps(AbstractBuild.java:720)
at hudson.model.Build$BuildExecution.post2(Build.java:185)
at hudson.model.AbstractBuild$AbstractBuildExecution.post(AbstractBuild.java:665)
at hudson.model.Run.execute(Run.java:1766)
at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43)
at hudson.model.ResourceController.execute(ResourceController.java:98)
at hudson.model.Executor.run(Executor.java:410)
Caused by: org.xml.sax.SAXParseException; systemId: file:/C:/Users/2554/.jenkins/workspace/TestProject/temporary-junit-reports/temp-junit.xml; lineNumber: 2; columnNumber: 3; Content is not allowed in prolog.
at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(Unknown Source)
at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(Unknown Source)
at javax.xml.parsers.DocumentBuilder.parse(Unknown Source)
at hudson.plugins.nunit.NUnitReportTransformer.splitJUnitFile(NUnitReportTransformer.java:102)
at hudson.plugins.nunit.NUnitReportTransformer.transform(NUnitReportTransformer.java:72)
at hudson.plugins.nunit.NUnitArchiver.invoke(NUnitArchiver.java:66)
... 13 more
Finished: FAILURE