When you try to connect Notion Calendar to your Google Calendar or Outlook Calendar, the sync may fail with a “Cannot connect” error. This usually happens because the calendar provider has revoked or restricted the permissions that Notion needs to read and write events. In this article, you will learn why these permission failures occur and how to fix them step by step. You will also find solutions for related connection problems and a comparison of Notion Calendar sync options.
Key Takeaways: Fixing Notion Calendar Sync Permission Errors
- Google Account > Third-party apps with account access > Notion Calendar: Remove and re-add Notion Calendar to reset the permission grant.
- Outlook > Settings > View all Outlook settings > Calendar > Connected accounts: Disconnect and reconnect the Notion Calendar integration to refresh the token.
- Notion Calendar > Settings > Connected calendars: Delete the broken connection and initiate a fresh OAuth authorization flow.
Why Notion Calendar Sync Fails Due to Permission Issues
Notion Calendar uses OAuth 2.0 to connect with Google Calendar and Outlook Calendar. This protocol requires the user to grant specific scopes, such as read and write access to calendar events. If the permission grant expires, is revoked by the user, or is invalidated by a change in the calendar provider’s policy, Notion Calendar can no longer fetch or update events. Common causes include password changes, account security reviews, and provider-side token expiration after a period of inactivity.
When the sync fails, Notion Calendar displays a “Cannot connect” error message. The underlying problem is almost always an outdated or missing OAuth token. The token is a digital key that Notion holds to prove it has your permission. If the token is rejected by Google or Microsoft, the connection breaks. Re-authorization through the correct settings pages restores the token and fixes the sync.
Steps to Reconnect Notion Calendar by Resetting Permissions
The following steps apply to both Google Calendar and Outlook Calendar connections. Perform them in the order shown. If the first method works, you do not need to proceed further.
Method 1: Re-authorize in Google Calendar
- Open your Google Account permissions page
Go to myaccount.google.com and sign in. Click Security in the left navigation. Scroll to Third-party apps with account access and click Manage third-party access. - Find and remove Notion Calendar
In the list of apps, locate Notion Calendar or Notion. Click the app name, then click Remove Access. Confirm the removal. - Return to Notion Calendar
Open Notion Calendar in your browser or desktop app. Go to Settings (gear icon) > Connected calendars. Find the broken Google Calendar connection and click Disconnect. - Reconnect your Google Calendar
Click Connect a calendar and select Google Calendar. A new browser window opens. Sign in to your Google account and grant the requested permissions. The sync should begin immediately.
Method 2: Re-authorize in Outlook Calendar
- Open Outlook account permissions
Go to account.microsoft.com and sign in. Click Privacy > Apps and services. Find Notion Calendar in the list of connected apps. - Remove the Notion Calendar app permission
Click Edit next to Notion Calendar, then click Remove these permissions. Confirm the removal. - Disconnect in Notion Calendar
Open Notion Calendar and go to Settings > Connected calendars. Select the Outlook connection and click Disconnect. - Reconnect your Outlook Calendar
Click Connect a calendar and choose Outlook Calendar. Sign in with your Microsoft account and accept the permission prompt. The sync resumes.
If Notion Calendar Still Cannot Connect After Permission Reset
Browser or App Cache Blocks the OAuth Redirect
Sometimes the browser or desktop app stores an old session that interferes with the new OAuth flow. Clear the cache for the Notion Calendar app or your default browser. In Chrome, go to Settings > Privacy and security > Clear browsing data and select Cached images and files. Restart Notion Calendar and try the reconnect steps again.
Account Has Two-Factor Authentication Blocking the Token
If you use two-factor authentication on your Google or Microsoft account, the OAuth flow may require an app password or a device-based approval. For Google, generate an app-specific password at myaccount.google.com > Security > App passwords. For Microsoft, use the Authenticator app to approve the sign-in request when prompted. After the app password is created, use it as the account password during the reconnect process in Notion Calendar.
Calendar Provider Has a Service Outage
Check the status pages for Google Workspace Status Dashboard or Microsoft 365 Service Health. If a known outage affects calendar APIs, the sync will fail regardless of permissions. Wait until the provider resolves the issue and then retry the connection.
Notion Calendar Sync Options: Google vs Outlook
| Item | Google Calendar | Outlook Calendar |
|---|---|---|
| OAuth scopes required | Read and write calendar events | Read and write calendar events |
| Two-factor authentication support | App password required | Authenticator app approval |
| Token expiration | 1 hour with refresh token | 90 days with refresh token |
| Permission revocation location | myaccount.google.com > Security > Third-party apps | account.microsoft.com > Privacy > Apps and services |
| Reconnection steps | Remove app access + disconnect in Notion Calendar + reconnect | Remove app permission + disconnect in Notion Calendar + reconnect |
After following the permission reset steps, your Notion Calendar should sync events without the “Cannot connect” error. If the problem persists, check the calendar provider’s service status and ensure your account is not locked due to security alerts. As an advanced tip, set a recurring monthly reminder to review connected apps in your Google or Microsoft account and remove any stale Notion Calendar entries before they cause a token conflict.