I get this error when trying to use a WebTab and No there is only one Register in the ascx page. Here is the header for my ascx page
<%@ Register Assembly="BMS.WebUI" Namespace="BMS.WebUI" TagPrefix="cc2" %>
<%@ Register Assembly="Infragistics35.WebUI.WebCombo.v8.1, Version=8.1.20081.1000, Culture=neutral, PublicKeyToken=7dd5c3163f2cd0cb" Namespace="Infragistics.WebUI.WebCombo" TagPrefix="igcmbo" %>
<%@ Register assembly="Infragistics35.WebUI.UltraWebGrid.v8.1, Version=8.1.20081.1000, Culture=neutral, PublicKeyToken=7dd5c3163f2cd0cb" namespace="Infragistics.WebUI.UltraWebGrid" tagprefix="igtbl" %>
Please help with why this would happen?
It seems that you have other class name(s) in the namespaces that you have included that are called Tab. In your code-behind, you can use the fully qualified name of the Tab (namespace + class name) to resolve that, e.g.
Infragistics.WebUI.UltraWebTab.Tab
Other things to check - currently you are refenrecing all Infragistics assemblies from cache - you can check your project references and make sure that CopyLocal is not set to true - this way you will have the same assemblies and /bin and GAC and this might be related to the issues you are having.