Forum Discussion
Error "CustomVisualNotFound" (Deneb 1.8.2.0)
Hi all
I've created a simple visual using Deneb (about 30 lines of spec in Vega Lite). This renders perfectly in Desktop, but doesn't in the Service, I get the above error. I've ran the issue by CoPilot and ruled out the suggestions (yes custom visuals are allowed, all in fact, not just certified which Deneb is). If I edit the report in the service (re-add the spec) it fixes it (for me) but then it's still broken for other users 😂 -- anyway, I've reverted to using a standard visual to get around this for now but would like to be able to use Deneb going forward -- any ideas?
Hi scone , Thank you for reaching out to the Microsoft Community Forum.
This isn’t an issue with your Vega-Lite spec or with Deneb being blocked. The Desktop-works but Service-fails and re-saving fixes it for me only pattern is a known Power BI Service behaviour with Deneb. It happens because the Service evaluates and caches the Vega-Lite spec differently than Desktop and those two environments are not always in lockstep.
When you re-edit the spec in the Service, it forces a recompile for your session, which is why it starts working for you but remains broken for other users. That strongly points to a Service side rendering or caching problem rather than anything wrong in the report itself.
Practically, the safest way to avoid this is to keep the spec fully explicit and conservative. Pin the Vega-Lite schema version, avoid newer or edge features and don’t rely on implicit defaults that Desktop tolerates. If you want a definitive call on your exact case, posting the spec and Service error to the Deneb GitHub issues page is usually the fastest way to confirm whether you’ve hit a Service limitation.
4 Replies
v-hashadapuCommunity Support
Hi scone , Thank you for reaching out to the Microsoft Community Forum.
This isn’t an issue with your Vega-Lite spec or with Deneb being blocked. The Desktop-works but Service-fails and re-saving fixes it for me only pattern is a known Power BI Service behaviour with Deneb. It happens because the Service evaluates and caches the Vega-Lite spec differently than Desktop and those two environments are not always in lockstep.
When you re-edit the spec in the Service, it forces a recompile for your session, which is why it starts working for you but remains broken for other users. That strongly points to a Service side rendering or caching problem rather than anything wrong in the report itself.
Practically, the safest way to avoid this is to keep the spec fully explicit and conservative. Pin the Vega-Lite schema version, avoid newer or edge features and don’t rely on implicit defaults that Desktop tolerates. If you want a definitive call on your exact case, posting the spec and Service error to the Deneb GitHub issues page is usually the fastest way to confirm whether you’ve hit a Service limitation.
- v-hashadapu
Hi scone , hope you are doing great. May we know if your issue is solved or if you are still experiencing difficulties. Please share the details as it will help the community, especially others with similar issues.
Hi - thanks for your answer, super helpful. The version is/was already pinned in the spec, but I've tried to stick to features that are core (not edge) and according to co-pilot this means:
1. No implicit defaults
Everything is explicitly declared:
- mark type
- axis objects (instead of null)
- color scale domain and range
- tooltip formats
Power BI Service is stricter about defaults than Desktop.
2. Avoids unsupported / unreliable features
Removed:
- "axis": null (can break on older runtimes)
- "view": {"stroke": "transparent"} (Service sometimes rejects this)
- mark shorthand { "line": true }
- newer conditional encodings
Replaced with explicit "axis": { labels: false } which Power BI handles reliably.
3. Stable color scale
The range [blue, green, red] is still preserved, but:
- domain is explicitly defined
- avoids multi-stop interpolation that older runtimes mishandle
4. Schema pinned to v5
Power BI tends to lag behind Vega-Lite releases — pinning v5 is safest.
5. No advanced config block
Power BI sometimes ignores or strips global config blocks ("config": {...}) in Service.
This version avoids them for reliability.Looking good so far, so I accept your answer!
- v-hashadapu
Hi scone , thanks for the update, happy to know your issue is sorted. If you have any other queries, pleae don't hesitate to create a new post here in the community. We are always happy to help.
