Using this reference:
<PackageReference Include="Syncfusion.Blazor.Diagrams" Version="19.2.0.62" />
I get this error in the browser console (Microsoft Edge Version 93.0.961.52 (Official build) (64-bit)):
blazor.server.js:1 [2021-09-22T23:11:13.667Z] Error: Microsoft.JSInterop.JSException: Could not find 'sfBlazor.callDiagramMethod' ('sfBlazor' was undefined).
Error: Could not find 'sfBlazor.callDiagramMethod' ('sfBlazor' was undefined).
at https://localhost:5001/_framework/blazor.server.js:1:497
at Array.forEach (<anonymous>)
at i.findFunction (https://localhost:5001/_framework/blazor.server.js:1:465)
at E (https://localhost:5001/_framework/blazor.server.js:1:2606)
at https://localhost:5001/_framework/blazor.server.js:1:3459
at new Promise (<anonymous>)
at Ct.beginInvokeJSFromDotNet (https://localhost:5001/_framework/blazor.server.js:1:3440)
at https://localhost:5001/_framework/blazor.server.js:1:70741
at Array.forEach (<anonymous>)
at Ct._invokeClientMethod (https://localhost:5001/_framework/blazor.server.js:1:70727)
at Microsoft.JSInterop.JSRuntime.InvokeAsync[TValue](Int64 targetInstanceId, String identifier, Object[] args)
at Syncfusion.Blazor.Diagrams.SfDiagram.UpdateDiagramObjects(Boolean IsAdding, Object[] methodParam)
at Syncfusion.Blazor.Diagrams.SfDiagram.UpdateCollection[T,R](T obj, R parent, Boolean isRemove)
at Microsoft.AspNetCore.Components.Rendering.RendererSynchronizationContext.ExecuteSynchronously(TaskCompletionSource`1 completion, SendOrPostCallback d, Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
at Microsoft.AspNetCore.Components.Rendering.RendererSynchronizationContext.ExecuteBackground(WorkItem item)