Jesse Glick added a comment - 2015-08-12 12:16 Probably caused by use of wildcards in the type.

Flávio Augusto Valones added a comment - 2015-08-12 17:44 - edited Hi Jesse, wildcards are not used in this case, it is a Map<String, String> . In the implementation of the AbstractStepImpl , if the map param is annotated in the field it works correctly, but if it is annotated in setter the error occurs. There are other parameters of types String , int and boolean , but these work normally whether annotated in the field or setter.

Jesse Glick added a comment - 2015-08-12 20:02 A bug in DescribableHelper that it throws this low-level exception, but I doubt it could work in any case. Jenkins has no databinding support for Map<String,String> . You must choose a type for which an actual /lib/form control exists.

Jesse Glick added a comment - 2015-08-12 20:04 (You could override StepDescriptor.newInstance and manually parse out content coming in from a Groovy script, but Snippet Generator will not work, so this is not a good idea.)

Flávio Augusto Valones added a comment - 2015-08-12 22:07 - edited Thanks for the reply, I use the Map<String, String> only as a workflow-step param, the conventional UI Builder uses only supported databinds compatible with /lib/form controls. Here's the code: public class SCTMStep extends AbstractStepImpl { private final int projectId; private final List< Integer > execDefIds; @DataBoundSetter public Map< String , String > params; @DataBoundSetter public String buildNumber; @DataBoundSetter public int delay; @DataBoundSetter public boolean continueOnError; @DataBoundSetter public boolean collectResults = true ; @DataBoundSetter public boolean ignoreSetupCleanup; @DataBoundConstructor public SCTMStep( final int projectId, final List< Integer > execDefIds) { this .projectId = projectId; this .execDefIds = execDefIds; } //getters for private fields @Extension(optional = true ) public static final class DescriptorImpl extends AbstractStepDescriptorImpl { public DescriptorImpl() { super (Execution.class); } @Override public String getFunctionName() { return "sctm" ; } @Override public String getDisplayName() { return Messages.getString( "SCTMExecutorDescriptor.plugin.title" ); } } public static final class Execution extends AbstractSynchronousStepExecution< Boolean > { private static final long serialVersionUID = 1L; @Inject private transient SCTMStep step; @StepContextParameter private transient TaskListener listener; @StepContextParameter private transient FilePath workspace; @StepContextParameter private transient Run<?, ?> run; @Override protected Boolean run() throws Exception { SCTMExe sctmExe = new SCTMExe(workspace, listener); sctmExe.execute(step.projectId, step.execDefIds, step.params, step.buildNumber, step.delay, step.collectResults, step.ignoreSetupCleanup, step.continueOnError, false ); if (step.collectResults) { sctmExe.publish(run); } return true ; } } } The databind of the Map<String, String> is done correctly and in the workflow Job this works like a charm: ... sctm projectId: 123, execDefIds: [456, 789], params: [NAME: 'Flávio Augusto Valones' , ADDR: 'Some Street' ] ... The sctm step is listed in the Snippet Generator (I have not yet implemented the jelly form for it), and everything goes as expected. The exception only occurs if I do this in the SCTMStep : ... private Map< String , String > params; @DataBoundSetter public void setParams(Map< String , String > params) { ... } ...