Forum Discussion

OliverFisher's avatar
OliverFisher
Copper Contributor
Oct 04, 2026

8 of 12 Copilot notebooks suddenly disappeared

Hello,

Today, 8 out of my 12 Copilot notebooks suddenly disappeared within a few minutes.

I have already verified the following:

  • The notebooks were visible shortly before they disappeared.
  • I did not delete any notebooks or chats.
  • The missing notebooks are not visible in either the Copilot Windows app or on copilot.com.
  • Searching for keywords that were definitely contained in those notebooks returns no results.
  • The remaining notebooks are still present and continue to contain their full chat history.
  • The behavior is identical across the Windows app and the web version.
  • I am signed into the correct Microsoft account.
  • The issue occurred around 10:00 PM local time.

In addition, approximately 90% of my chat history has disappeared. Only a small number of chats remain visible.

The missing notebooks were actively used project notebooks, while most of the remaining notebooks are older ones that I had not used recently.

I'm particularly concerned because the notebooks and chats disappeared without any user action and were still visible only minutes before.

Questions:

  1. Has anyone experienced notebooks disappearing like this?
  2. Did the notebooks or chats reappear later without intervention?
  3. Is there any recovery option for missing notebooks and chat history?
  4. Could this be a synchronization, indexing, migration, or backend issue?

I have screenshots documenting the issue and timeline.

Any advice or similar experiences would be greatly appreciated.

Thank you.

1 Reply

  • Eforest's avatar
    Eforest
    Copper Contributor
    Oct 23, 2026
    1. I have the same issue and I'm still not sure what caused it and why I was able to resolve it. After the first one disappeared, I tried to access the remaining ones and they disappeared as soon as I opened them and returned to the list.
    2. They occasionally reappeared and I was able to keep those that I added to my favorites. If I didn't, they disappeared once again. This way I was able to keep one for some time and hoped that the others would appear again.
    3. There seems to be no official way to resolve this, I'm not sure if there is any way to restore vanished chat histories, however today I realized that my chat history contained chats that I started in said vanished notebooks and prompted something like "A quick off-topic question: As far as I recall, I started this chat in a notebook, but I can no longer find it. Do you still have this context?" some chats said yes, and even listed IDs, some said that they don't know directly, but have other chats as reference. But prompting this somehow triggered the backend to restore the notebook each chat was related to. I restored 5 notebooks this way.
    4. I don't know what Microsoft would call that, but it's definitely not a client issue, since those notebooks weren't visible in any of my clients. I tried Android, Web, Desktop and even OneNote before and after restoring.

    I hope this helps in any way and I wish you good luck.