topic Re: CreateRenderer Failing in ArcGIS Pro SDK Questions

CreateRenderer Failing

MichaelTodd — Tue, 18 Nov 2025 17:48:59 GMT

Under what circumstances would a layer CanCreateRenderer method return true, yet running CreateRenderer with the same renderer caused the following error:

ArcGIS.Desktop.Mapping.MappingException: 'Error HRESULT E_FAIL has been returned from a call to a COM component.'

Can't nail down why the error. Everything seems to be set up correctly, using a FeatureLayer, all required elements are set in the classes. To top it off, this code has been working since at least ArcGIS Pro 2.8 and has just recently started to crash Pro. Any ideas?

Re: CreateRenderer Failing

UmaHarano — Wed, 19 Nov 2025 20:46:48 GMT

Can you please share your code and the type of layer you are rendering?

Re: CreateRenderer Failing

GKmieliauskas — Wed, 19 Nov 2025 20:47:37 GMT

Hi,

Some information from ArcGIS Pro API:

Certain renderers are only appropriate for certain layer types or for layers of a certain geometry type. For example a Dot Density Renderer can only be applied to a polygon layer, a Heat Map Renderer can only be applied to a point layer.

Please give us more information about your layer shape type, renderer type and etc.

Re: CreateRenderer Failing

MichaelTodd — Wed, 19 Nov 2025 21:42:03 GMT

I'll provide more details, including the code, in the other response in a moment, but my real question, given your statement, is: what utility does the CanCreateRenderer method provide if it returns true, yet the CreateRenderer method fails when using the same ValueRenderer in both cases? If it had responded with false, I would have looked deeper into the code (which, again, has been working with the same layer for about 4 years now) as the source of the problem. As it stands, I cannot rely on CanCreateRenderer to vet whether or not the renderer I created is valid with the layer in question.

Re: CreateRenderer Failing

MichaelTodd — Wed, 19 Nov 2025 21:45:35 GMT

The layer I am trying to alter is a polyline. I am using a UniqueValueRenderer with one field and five values to differentiate symbology. And, again, this code has worked for about four years now, with no changes to it, so I am unclear why it is failing with that error now. Code is attached.

Re: CreateRenderer Failing

UmaHarano — Thu, 20 Nov 2025 18:32:48 GMT

Hi @MichaelTodd

The CanCreateRenderer method checks if the renderer being applied to the layer is the appropriate choice -
Certain renderers are only appropriate for certain layer types or for layers of a certain geometry type. For example a Dot Density Renderer can only be applied to a polygon layer, a Heat Map Renderer can only be applied to a point layer.

The method does not check if all the renderer values being applied are correct - such as are the correct fields being used, etc.

Re: CreateRenderer Failing

MichaelTodd — Thu, 20 Nov 2025 18:37:48 GMT

Got it, though given that result I would expect the method to be named "IsValidRendererType", not "CanCreateRenderer". Neither here nor there, of course.

Have you had an opportunity to examine the code? Is there anything that stands out as being jarringly incorrect? I will say that "status" is a valid field, and the symbologies (to my eye) also appear valid. Just can't narrow down what's causing the failure to create the renderer.

Re: CreateRenderer Failing

UmaHarano — Fri, 21 Nov 2025 18:57:09 GMT

@MichaelTodd
I used your code on a mock up data set with "status" fields. It seems to work for me. I can't see anything wrong with the code. We will have to debug with your data to see what is actually happening.

Re: CreateRenderer Failing

GKmieliauskas — Sun, 23 Nov 2025 13:35:59 GMT

Hi,

I have tested your code on ArcGIS Pro 3.5 and can say the same as @UmaHarano . It works as in Uma's screenshot.

What version of ArcGIS Pro do you use?

Re: CreateRenderer Failing

MichaelTodd — Mon, 24 Nov 2025 15:02:28 GMT

I am using ArcGIS Pro 3.5.4.57366.

Re: CreateRenderer Failing

MichaelTodd — Mon, 24 Nov 2025 15:06:53 GMT

Attached is a file geodatabase with the two files in question. I assume the code will work with them since they were exported to a file geodb. I have a feeling that the layers themselves, currently living in our Enterprise geodb (Sql Server) are corrupted (usable, but corrupted). If the attached layers work, I would hazard that as being the case.
If so, I suppose the next step is: how do I fix those layers in the Sql Server without breaking things?

Re: CreateRenderer Failing

MichaelTodd — Mon, 24 Nov 2025 15:07:31 GMT

Because, of course I forgot the attachment.

Re: CreateRenderer Failing

GKmieliauskas — Mon, 24 Nov 2025 17:49:35 GMT

Your code works with file gdb you attached.

Check your map content for broken layers. If they exist, remove them and try your code