All the users in my tenat aren't able to login to Sharepoint and Onedrive getting a redirectUriMismatchError

Dear @Stefano Branchi,

Based on your description, it seems you're encountering a redirect URI mismatch error when accessing SharePoint and OneDrive. 

To help us investigate further, could you please follow the steps below:

1. Access Microsoft Graph Explorer via this link: https://developer.microsoft.com/en-us/graph/graph-explorer/ 

2. Sign in using your Global Administrator account. 

3. Once signed in, go to Modify Permissions. 

• In the Status column, please click Consent to allow access to run queries. 
• On my screen, I’ve already completed the consent, so the status shows Unconsent.

4. Next, please add the following API query: 

GET https://graph.microsoft.com/v1.0/servicePrincipals?$filter=appId eq '00000003-0000-0ff1-ce00-000000000000' 

This should look similar to the screenshot below: 

Click Run Query. 

1. After receiving the response, please scroll down and locate the ReplyURLs section. 
2. Kindly take a screenshot of the ReplyURLs and send it to us via Private Message (you can find this option above your title).

Let us know once completed or if you encounter any issues during the process. 

If you have extra questions about this answer, please click "Comment". 

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