I am using Sitecore 8.2 rev. 170614. Recently I am seeing below errors in Production CM server Logs,

ManagedPoolThread #0 00:50:26 ERROR One or more exceptions occurred while processing the subscribers to the 'wffm:action:remote' event.
Exception[1]: System.InvalidOperationException 
Message[1]: There is an error in XML document (2, 13). 
Source[1]: System.Xml 
   at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader, String encodingStyle, XmlDeserializationEvents events)
   at System.Xml.Serialization.XmlSerializer.Deserialize(TextReader textReader)
   at Sitecore.Form.Core.WffmActionHandler.<OnWffmActionEventFired>b__4(ControlResult f)
   at Sitecore.ContentSearch.Utilities.EnumerableExtensions.ForEach[T](IEnumerable`1 collection, Action`1 action)
   at Sitecore.Form.Core.WffmActionHandler.OnWffmActionEventFired(Object sender, EventArgs args)
   at Sitecore.Events.Event.EventSubscribers.RaiseEvent(String eventName, Object[] parameters, EventResult result) 

ManagedPoolThread #0 00:50:26 ERROR Exception while handling event Sitecore.Form.Core.WffmActionEvent
Exception: System.AggregateException
Message: One or more exceptions occurred while processing the subscribers to the 'wffm:action:remote' event.
Source: Sitecore.Kernel
   at Sitecore.Events.Event.EventSubscribers.RaiseEvent(String eventName, Object[] parameters, EventResult result)
   at Sitecore.Events.Event.RaiseEvent(String eventName, Object[] parameters)
   at Sitecore.Eventing.Subscription`1.Invoke(Object instance, EventContext context)
   at Sitecore.Eventing.EventProvider.RaiseEvent(Object event, Type eventType, EventContext context)

Any guidance would be helpful.


3 Answers 3


Sitecore tries to enumerate all the fields in remote event and process them.

One of the fields contains a serialized value which is not a valid xml.

When WFFM serialize the value, it uses quite stupid mechanism - it just wrapps whatever comes from the form in <item> tag.

Most probably one of your fields contains value which is not valid inside html. That can be e.g. < or > character, or maybe unescaped & character or something like that.

Find which field is causing the issue by removing fields one by one from the form (or maybe check the form report) and make sure that whatever is the value of that field, is properly encoded so it doesn't break remote actions.


I've seen this error before and in our case, it was due to the Incorrect patching order of Sitecore.Forms.CD.config.

To resolve the issue, we rename the \App_Config\Modules\Wffm\Sitecore.Forms.CD.config file so that it becomes the last one in that folder (for example, to z.Sitecore.Forms.CD.config).

Reference: https://support.sitecore.com/kb?id=kb_article_view&sysparm_article=KB0223343

Hope it helps!


Sitecore provides multi-server support for WFFM so the following is the standard configuration setting for different servers. You can verify these settings on your servers.

CM Server Configurations

If you have one or more CM servers then you have to configure following settings.

On one server only, in the \App_Config\Include\Sitecore.Forms.config file,

In the <sitecore> section, add following

<!--remote events hook-->

<hook type="Sitecore.Form.Core.WffmActionHook, Sitecore.Forms.Core"/> </hooks>

And in the <events> section, add

<!--Remote events handler-->

<event name="wffm:action:remote">

<handler type="Sitecore.Form.Core.WffmActionHandler, Sitecore.Forms.Core" method="OnWffmActionEventFired" >

<param name="actionManager" ref="/sitecore/wffm/wffmActionExecutor" />



This basically will get the events from EventQueue and process WFFM events.

Also ensure that following setting is not there on any CM server, in the <settings> section.

<setting name="WFM.IsRemoteActions" value="true" />

Above setting disable firing the action events of WFFM on CM server. You need this setting on CD server where you need to fire RemoteEvent.

Refer to this article for both server configurations in more detail.


Hope this helps.

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