Plugin Controller - Save Entry
You're likely getting a validation error that you're not checking for.  Do something like this:

if ($entry-&gt;validate())
{
    $service-&gt;saveEntry($entry);
}
else
{
    $errors = $entry-&gt;getErrors();
}


Update:

Do you get anything if you do:

if (!$service-&gt;saveEntry($entry))
{
    $errors = $entry-&gt;getErrors();
}