RSS Feed Issue

I am trying to create a RSS feed from an outside source that we are pulling into our website.  When I create the rss feed it is giving me this error.

 Server Error in '/' Application.
Specified cast is not valid.
Description: An unhandled exception occurred during
the execution of the current web request. Please review the stack trace
for more information about the error and where it originated in the
code.
Exception Details: System.InvalidCastException: Specified cast is not valid.
Source Error:
An unhandled exception was generated during the execution of the current
web request. Information regarding the origin and location of the
exception can be identified using the exception stack trace below.
Stack Trace:
[InvalidCastException: Specified cast is not valid.]
Telerik.Sitefinity.Publishing.Pipes.RSSOutboundPipe.BuildSyndicationItem(WrapperObject values) +1497
Telerik.Sitefinity.Publishing.Pipes.RSSOutboundPipe.BuildSyndicationItems(IEnumerable`1 internalFormat) +130
Telerik.Sitefinity.Publishing.Pipes.RSSOutboundPipe.BuildSyndicationFeed(IEnumerable`1 items) +591
Telerik.Sitefinity.Publishing.Pipes.RSSOutboundPipe.GetData() +989
Telerik.Sitefinity.Publishing.Web.FeedFormatter.GetFeedFormatter(IPipe pipe) +47
Telerik.Sitefinity.Publishing.Web.PublishingHttpHandler.HandleRequest(IPipe pipe, HttpResponse response) +180
Telerik.Sitefinity.Publishing.Web.PublishingHttpHandler.ProcessRequest(HttpContext context) +1215
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +625
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +270

Any ideas on what steps I need to take to fix this? Thank you for the help

Hello Zach,

We are not able to replicate this issue locally. Most likely there is something in the feed causing this unusual behavior. Can you provide us some steps to reproduce and also what is the project version you are using?

Regards,
Vassil Vassilev
Telerik