The server tag 'ej:Button' is ambiguous. Please modify the associated registration that is causing ambiguity and pick a new tag prefix.

[Zaid]

I have all the required assemblies and name spaces but still getting the error.

<add assembly="Syncfusion.EJ, Version=14.4460.0.15, Culture=neutral, PublicKeyToken=3d67ed1f87d44c89" />
        <add assembly="Syncfusion.EJ.Web, Version=14.4460.0.15, Culture=neutral, PublicKeyToken=3d67ed1f87d44c89" />

<add namespace="Syncfusion.JavaScript.Web" assembly="Syncfusion.EJ.Web, Version=14.4460.0.15, Culture=neutral, PublicKeyToken=3d67ed1f87d44c89" tagPrefix="ej"/>
        <add namespace="Syncfusion.JavaScript.Web" assembly="Syncfusion.EJ, Version=14.4460.0.15, Culture=neutral, PublicKeyToken=3d67ed1f87d44c89" tagPrefix="ej"/>
        <add namespace="Syncfusion.JavaScript.Models" assembly="Syncfusion.EJ, Version=14.4460.0.15, Culture=neutral, PublicKeyToken=3d67ed1f87d44c89" tagPrefix="ej"/>

[Francis Paul Antony Raj]

Hi Zaid, 

 

Thanks for contacting Syncfusion Support. 

 

We suspect that the reported issue (Parser Error Message: The server tag 'ej:Button' is ambiguous. Please modify the associated registration that is causing ambiguity and pick a new tag prefix.) occurs due to multiple repeated Syncfusion assembly references in your project. 

 

Could you please check and make sure that you are not referencing another version of Syncfusion.EJ.Web dll anywhere in the project. Also, clean the ‘bin’ and ‘obj’ folder and run the application properly. 

 

[web.config] – remove the repeated assembly reference 

<controls> 

        <add namespace="Microsoft.AspNet.Web.Optimization.WebForms" assembly="Microsoft.AspNet.Web.Optimization.WebForms" tagPrefix="webopt" /> 

        <add namespace="Syncfusion.JavaScript.Web" assembly="Syncfusion.EJ.Web, Version=14.4451.0.15, Culture=neutral, PublicKeyToken=3d67ed1f87d44c89" tagPrefix="ej" /> 

        <add namespace="Syncfusion.JavaScript.Web" assembly="Syncfusion.EJ.Web, Version=14.3451.0.52, Culture=neutral, PublicKeyToken=3d67ed1f87d44c89" tagPrefix="ej" /> <!--please remove this assembly if it is referred as duplicate in anywhere in this project--> 

        <add namespace="Syncfusion.JavaScript.Models" assembly="Syncfusion.EJ, Version=14.4451.0.15, Culture=neutral, PublicKeyToken=3d67ed1f87d44c89" tagPrefix="ej" /> 

        <add namespace="Syncfusion.JavaScript.Web" assembly="Syncfusion.EJ, Version=14.4451.0.15, Culture=neutral, PublicKeyToken=3d67ed1f87d44c89" tagPrefix="ej" /> 

</controls> 

 

If still issue persists, please provide an information about when you are facing the issue (like during project migration or project conversion). This will be helpful for us to analyze and provide a solution at the earliest. 

 

Regards, 

Francis Paul A.