Hi,

I am upgrading from version 7.1 to 7.5. We have few gadgets added in the project like Sources Gadget, "Page Information Gadget", "bulk publishing" but they are generating errors after
the upgrade. Any idea thank you so much in advance. It generates errors as soon as I click on UI .  Any bright ideas?

The error is as follows:-
Server Error in '/' Application.

Cannot find ContentPlaceHolder 'head' in the master page '/EPiServer/CMS/MasterPages/EPiServerUI.Master', verify content control's ContentPlaceHolderID attribute in the content page.

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.Web.HttpException: Cannot find ContentPlaceHolder 'head' in the master page '/EPiServer/CMS/MasterPages/EPiServerUI.Master', verify content control's ContentPlaceHolderID attribute in the content page.

Source Error:

Submit
Stack Trace:

[HttpException (0x80004005): Cannot find ContentPlaceHolder 'head' in the master page '/EPiServer/CMS/MasterPages/EPiServerUI.Master', verify content control's ContentPlaceHolderID attribute in the content page.]
   System.Web.UI.MasterPage.CreateMaster(TemplateControl owner, HttpContext context, VirtualPath masterPageFile, IDictionary contentTemplateCollection) +1085
   System.Web.UI.Page.ApplyMasterPage() +75
   System.Web.UI.Page.PerformPreInit() +211
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1844

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.34209              

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