Virtual Agent Designer – Unhandled Exception: TypeError: Cannot read property "label" from null

[KaushikR]

When attempting to open a topic in the Virtual Agent Designer, the designer fails to load and throws the following error:

> Unhandled exception
> TypeError: Cannot read property "label" from null

The topic tab opens in the designer but the canvas remains blank, and only the error illustration is displayed. The topic was previously working and no recent changes were made to it intentionally.

Steps to Reproduce:
1. Navigate to Virtual Agent > Designer
2. Open the affected topic
3. Designer canvas fails to render and shows "Unhandled exception" with the TypeError

Questions:
1. Has anyone encountered this `TypeError: Cannot read property "label" from null` in Virtual Agent Designer?
2. Is there a known broken node type or configuration that causes this?
3. Is there a way to identify and fix the null reference without rebuilding the entire topic?
4. Could this be related to a Now Assist skill being misconfigured or pointing to a null record?

Any guidance or pointers would be greatly appreciated. 

Thanks in advance!

[Dr Atul G- LNG]

Try repair the VA plugin.

[SohamTipnis]

Hi @KaushikR,

I think it's a problem in your PDI because I can see that in my PDI designer. So I will suggest you try to repair it or simply refresh your PDI instance. Both of these can be helpful.

If you find my answer useful, please mark it as Helpful and Correct. ‌‌‌‌‌‌‌😊

Regards,
Soham Tipnis
ServiceNow Developer ||  Technical Consultant
LinkedIn: www.linkedin.com/in/sohamtipnis10

[karunakar_O]

Please repair these plugins
1. sn_udc

2. sn_convo_studio

And then try to import this file from any out of the box developer instance
sys_id: cf28760743230210a9c8b5d31cb85d31cb8f2e5

That should solve your issue.