Why diagram nodes or connectors are not properly displayed in a web page?

Why diagram nodes or connectors are not properly displayed in a web page?

You should add correct httphandler in the web.config file of your application, for the model to render the nodes properly. Refer to the below code for a correct httphandler.

<httphandlers>

<add verb="*" path="ImgRequest.ashx" type="Syncfusion.Web.UI.WebControls.Diagram.NodeRenderHandler, Syncfusion.Diagram.Web, Version=7.103.0.21, Culture=neutral, PublicKeyToken=3d67ed1f87d44c89"/>

</httphandlers>

For PaletteGroupbar and OverviewControl, you should add the following httphandlers.

<add verb="*" path="PaletteImgRequest.ashx" type="Syncfusion.Web.UI.WebControls.Diagram.ThumbNodeRenderHandler, Syncfusion.Diagram.Web, Version=7.103.0.21, Culture=neutral, PublicKeyToken=3d67ed1f87d44c89"/>

<add verb="*" path="OverviewImgRequest.ashx" type="Syncfusion.Web.UI.WebControls.Diagram.OverviewDocumentRenderHandler, Syncfusion.Diagram.Web, Version=7.103.0.21, Culture=neutral, PublicKeyToken=3d67ed1f87d44c89"/>