UiPath errors / Version
XamlObjectWriterException: Cannot create unknown type (activity)
Cause
The Robot/Orchestrator runtime runs an older activity package that does not recognise activity types from the newer package used at development time.
Fix
Align Studio, Robot, and Orchestrator on compatible versions. In Studio's Manage Packages, downgrade UiPath.UIAutomation.Activities and UiPath.System.Activities to versions the Orchestrator supports, re-publish, and re-trigger. If already aligned, clear the Robot's NuGet cache (%userprofile%\.nuget\packages\) to force a fresh download.
Part of the Automation Error Index — UiPath errors: browse all.
Hitting an automation error we have not covered?
AutomateLab builds and debugs n8n, Make, and agent workflows as fixed-scope projects. If something is broken in production, tell us what you are seeing.
Describe the problem