An application or feature powered by Windows Copilot to assist users with tasks and productivity
Hi Marie Sinfield,
I can see why this particular conversation is important, especially since it is still listed in your history and briefly begins loading before the interface becomes unresponsive.
Based on the behavior you described, this appears more consistent with a rendering or performance limit affecting that exceptionally large thread than with a general Copilot, browser, or connectivity problem. The fact that the same conversation fails in both the desktop app and the web interface, while other conversations remain accessible, also suggests that reinstalling the app or clearing the browser cache may have limited value.
There is no publicly available user-facing tool for splitting, rebuilding, or reindexing an individual Copilot conversation. It is also not possible from this user-to-user forum to confirm whether Microsoft has an internal process that can perform those operations on a specific thread.
Before taking any further action, I would recommend exporting your Copilot activity history through the Microsoft Privacy Dashboard. The exported data may help preserve prompts and responses that can still be retrieved from the service, although it may not reproduce the original conversation layout or restore the thread to a renderable state. Microsoft provides more information here: Manage your Copilot activity history in the privacy dashboard.
You should also report the affected conversation through Send feedback > Report a problem in Copilot. Include the conversation title, its approximate size, the browsers and app versions tested, the approximate time it last opened successfully, and a screenshot showing the blank page or Page Unresponsive message. These details will help distinguish a thread-size limitation from an issue with the stored conversation data.
Please avoid deleting the conversation or clearing all Copilot activity history while attempting to preserve it. For future reference, saving long-running research in separate conversations or periodically copying important sections into a document can reduce the risk of a single thread becoming too large for the interface to render. Thank you so much for your understanding.
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