Hi there,

I've seen the below stacktrace:

Caused by: java.lang.ClassCastException: hudson.model.labels.LabelExpression$And cannot be cast to hudson.model.labels.LabelAtom

Which it's caused when using doublequotes restricted labels:

When I debugged I saw the below details:

Unfortunately I wasn't able to reproduce in my test scenario with something like:

@Test public void testWithDoubleQuoteAssignedLabel() throws Exception {
    FreeStyleProject project = j.createFreeStyleProject();
    j.createSlave("test",null);
    project.setAssignedLabel(j.jenkins.getLabel("\"linux && !reserved\""));
    assertFalse(checker.executeCheck(project));
}

It looks like it is caused by: https://github.com/jenkinsci/jenkins/blob/master/core/src/main/java/hudson/model/AbstractProject.java#L413  and when configuring jobs using the WebUI. 

Workaround: 

• If i use "getAssignedLabel().getName()" I don't see that error...

Please find attached the maven dependencies tree

If you need further details please let me know

Thanks