Sometimes the account entry inside the new Outlook is what is damaged. Removing and re-adding it rebuilds everything cleanly — here is the safe order, and the one check to do first.
Restarts did nothing and the same account keeps failing in the new Outlook. The next honest step is to remove the account from the app and add it again, so its settings and synced copy are rebuilt from the server. Done in the right order, this costs you nothing but sync time.
Removing and re-adding is safe because the new Outlook is server-based: for Outlook.com, Microsoft 365, Gmail and IMAP accounts, the real mailbox sits on the server and the app holds a synced copy. One honest exception deserves ten seconds: if you ever moved mail into folders that exist only on this PC — an old POP setup or a local archive habit — export or copy that mail somewhere safe before removing anything. Server mail re-syncs; local-only mail does not.
olk.exe and end it if it lingers.Open the new Outlook, go back to Settings → Accounts, and add the account with its email address and password, completing any sign-in or verification prompts. Adding it fresh rebuilds the account's local registration and synced copy from zero — which is exactly what clears account-level corruption that survives ordinary restarts.
A re-added mailbox is not instant. Headers arrive first, then messages, then attachments and older mail work their way down. On a large mailbox or slow connection this can run for a long while, and folders can look empty mid-sync. Leave the app open, watch the sync status settle, and only then test the folder that originally failed with Cannot display the folder.
Then the account was never the problem. A clean re-add that still fails points back at the two usual suspects: the app installation itself (use the Repair, then Reset, route from Settings) or the cross-app conflict with classic Outlook over a shared data file (the main guide's fix). Do not keep removing and re-adding in a loop — each cycle costs a full re-sync and tells you nothing new.
The video covers the conflict side of this error family — this account rebuild pairs with it when one app alone keeps failing.
▶️ Watch Full VideoFor server-based accounts — Outlook.com, Microsoft 365, Gmail, IMAP — no. The mailbox stays on the server and downloads again. Only mail that exists solely on this PC needs a backup before you start, which is why step one exists.
It depends on mailbox size and connection speed. Small mailboxes settle in minutes; large ones can take much longer. Leave the app open and let the sync status finish before testing.
Then the account was not the fault. Repair or reset the app itself, and if classic Outlook is also on the PC, check for the shared data file conflict covered in the main guide.