“Open the tool pane” javascript error in SharePoint 2010

I was running into trouble when using the out-of-the-box RSS Feed Web Part of SharePoint 2010 on a publishing page. Especially when the Web Part wasn’t configured with a RSS feed, because it shows the following message:

If you want to configure the RSS Web Part, you click “Open the tool pane” link. However it displays the following javascript errors:

 

Not much help in this error. A work-around would be to set the publishing page in Edit mode, and than click the “Open the tool pane” link. Not very user friendly.

The “open the tool pane” link calls a function MSOTlPn_ShowToolPane2. Strange thing is that when the Publishing Page is in Edit mode and clicking the “open the tool pane” link doesn’t raise the error. After some research I found out that the “Edit mode” includes a javascript file named “ie55up.js”.

I included the ie55up.js in the Master Page using the <SharePoint:ScriptLink> and it solved the problem.

<SharePoint:ScriptLink language="javascript" name="ie55up.js" OnDemand="false" runat="server" />

Make sure you set OnDemand="false", otherwise the javascript file will not be loaded.