Online Mode isn't turn on, so some functionality may not be available on OneDrive

Test OneDrive from the iPad over a different network—preferably a phone hotspot—because failure in multiple browsers and on iOS makes the current network path or a service/account issue more likely than browser cache.

1. Isolate the network

1. Disconnect the iPad from its current Wi-Fi.
2. Connect it to a mobile hotspot or unrelated Wi-Fi network.
3. Open the OneDrive app and try signing in.
4. Also open https://onedrive.live.com/ in Safari.

Microsoft specifically recommends a hotspot test when OneDrive reports that it is not connected.^1^

• If OneDrive works on the hotspot: the original network likely has DNS, firewall, VPN, web-filtering, parental-control, or ISP interference. The hotspot is a diagnostic test and temporary workaround; the permanent fix is to correct the original network.
• If it fails on both networks: continue with the account, service-health, and iOS checks below.

If testing requires disabling a VPN or security/web-filtering feature, do so only briefly and re-enable it immediately afterward. Prefer having the network administrator add the required OneDrive endpoints to an allowlist.

2. Apply the correct account-specific network checks

Determine which account is affected:

• Personal OneDrive: normally signs in with a personal Microsoft account.
• Work or school OneDrive: supplied and managed by an employer or school.

For a personal account:

1. Sign in to the Microsoft Account dashboard to verify that the credentials and account are working.
2. If access works on a hotspot but not the original network, check whether its firewall or filtering allows the consumer OneDrive hosts over TCP ports 80 and 443. Microsoft publishes the applicable host list.^2^
3. If you use BT Broadband, verify whether BT Web Protect is enabled. Microsoft documents that it can block OneDrive at the network level.^3^ Disable it only long enough to test, restore it afterward, and contact BT for a narrower configuration if that confirms the issue.

For a work or school account, do not use the consumer endpoint list. Ask the Microsoft 365/network administrator to:

1. Open Microsoft 365 admin center → Health → Service health.
2. Check active incidents or advisories for OneDrive and SharePoint Online.
3. If no incident exists, validate the network against Microsoft’s Microsoft 365 URLs and IP address ranges, rather than the consumer OneDrive list. Service-health information requires an appropriate admin role.^4^

If the admin center itself is inaccessible, Microsoft’s public service status page can show known sign-in problems.^4^

3. If the browser specifically reports a DNS error

If the Windows browser shows DNS_PROBE_FINISHED_NXDOMAIN, server not found, or site can’t be reached:

1. First verify that the Microsoft 365 subscription is active.
2. On Windows, select Start, enter cmd, and open Command Prompt.
3. Run:

ipconfig /flushdns

4. Close and reopen the browser, then test OneDrive again.

Microsoft documents subscription state and stale local DNS as possible causes for this specific symptom.^5^

4. Reset OneDrive on the iPad

If OneDrive still fails on the iPad even over a different network:

1. Open OneDrive → Profile → Settings → Account.
2. Select the affected account if more than one is configured.
3. Select Reset.
4. Try signing in again.

If resetting does not help, uninstall OneDrive, restart the iPad, and reinstall OneDrive from the App Store. Resetting or reinstalling affects the local app state; files already stored in OneDrive remain online, although app preferences may need to be configured again.^6^

If it still fails on unrelated networks after the account and service checks, contact Microsoft Support for a personal account or the organization’s IT administrator for a work/school account, providing the exact browser and iPad error text.

References

1. Troubleshoot OneDrive for iOS app problems | Microsoft Support
2. Required URLs and ports for OneDrive
3. Overview
4. How to check Microsoft 365 service health
5. Error 'DNS_PROBE_FINISHED_NXDOMAIN' when accessing OneDrive or Sharepoint
6. [iOS](https://support.microsoft.com/onedrive/reset-onedrive#to-reset-onedrive-on-ios)