Steps to Reproduce

Run fiddle in local environment
http://zkfiddle.org/sample/16b7anl/1-paramCall-output-exception-to-console
(note: fiddle == smallest reproducing code. Same issue triggered by more complicated constraint checks)

Current Result

paramCall.call() outputs caught Expectable exceptions to console.

Expected Result

Expectables shouldn't be output to console, such as with the regular UiEngine (see org.zkoss.zk.ui.impl.UiEngineImpl.handleError(Throwable, UiVisualizer, List<Throwable>) for usual handling)

Debug Info

org.zkoss.bind.impl.ParamCall.call(Object, Method) is catching InvocationTargetException which is an expectable, and logging it to Logger.error()
Should be at most logger.debug()
However, the catch block for the general exception type (java.lang.Exception) should still log to Logger as logger.error(), as they are not expected

Root Cause

Innacurate logger level used

Workaround

Disable log for package / class
Ex: in log4j:

log4j.logger.org.zkoss.bind.impl = OFF