When a server-side error occur in Liferay, a default message could be shown to the user: “Your request failed to complete.”
This message is displayed when an exception is not planned to be thrown in the current JSP. If you want to understand how and when this default message is displayed, have a look at the file “/html/taglib/ui/error/end.jsp”.
Hide the default error message in a specific page
Use this snippet in the controller of your portlet when you want to hide the default error message in a specific case :
(If you want to understand how it works, check the code of “/html/common/themes/portlet_messages.jspf” and search “KEY_SUFFIX_HIDE_DEFAULT_ERROR_MESSAGE”)
Hide the default error message in every page
If you want to hide this error message everywhere in the portal you just have to edit the file “taglib/ui/error/end.jsp” via a hook.
The default error message is generated in this file (this JSP is a part of the taglib “liferay-ui:error”)