# AUR3351 ## Error Message `AUR3351: Unexpected viewport deactivation outside of a transition context at %s` ## Description This error indicates the router attempted to deactivate a viewport outside of an active transition context. This typically points to an internal state issue. ## Troubleshooting * If you can reproduce this reliably, please report it with a minimal reproduction. * Review custom router/viewport integrations for direct calls into viewport agent internals. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.aurelia.io/developer-guides/error-messages/router/aur3351.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.