ASPxPage Control Cannot unregister UpdatePanel

I recently had a problem when using the Devexpress Page control wiht update panels in the pages. I have code to hide/show tabs based on certain settings, but the error: Cannot unregister UpdatePanel with ID 'upLoginActivityGrid' since it was not registered with the ScriptManager. This might occur if the UpdatePanel was removed from the control tree and later added again, which is not supported. Parameter name: updatePanel was shown by the .net runtime. after a little investigation this can easily be solved by hiding the tabs client side rather than server side. so changing the code from this: to this: solves the problem