Fix issue processwire/processwire-issues#1712

wire/modules/Process/ProcessPageList/ProcessPageList.module

@@ -179,6 +179,10 @@ class ProcessPageList extends Process implements ConfigurableModule {
 		if($langID) $this->wire('user')->language = $this->languages->get($langID);
 		$this->trashLabel = $this->_('Trash'); // Label for 'Trash' page in PageList // Overrides page title if used
 	
+		/** @var JqueryUI $jQueryUI */	
+		$jQueryUI = $this->wire()->modules->get('JqueryUI');
+		$jQueryUI->use('vex'); // for alert boxes
+		
 		$id = $input->get('id');
 		if($id === 'bookmark') $this->wire('session')->redirect('./bookmarks/');
 		$id = (int) $id; 

wire/templates-admin/scripts/main.js

@@ -497,6 +497,12 @@ if(typeof ProcessWire != "undefined") {
 			if(allowMarkup) {
 				vex.dialog.alert({unsafeMessage: message});
 			} else {
+				if(message.indexOf('&') > -1 && message.indexOf(';') > 1) {
+					// remove entitity encoded sequences since Vex already encodes
+					var v = document.createElement('textarea');
+					v.innerHTML = message;
+					message = v.value;
+				}
 				vex.dialog.alert(message);
 			}
 		} else {