Troubleshooting: Unable to Establish Connection with Microsoft 365 Organization

Unable to Establish Connection with Microsoft 365 Organization

KB ID: 303004
Cause:
This error arises when the backup server encounters difficulties in connecting to the Microsoft 365 Organization. The issue can be attributed to one or more of the following factors:
1. Invalid Tenant ID, Application ID, and Secret Key: The credentials provided for connecting to Microsoft 365 might be incorrect.
2. System Clock Synchronization: The system clock on the backup server may not be synchronized with internet time.
3. Invalid SSL Certificate File (.pfx) and Password (Applicable if Application Certificate is selected):
   a. The provided SSL certificate file (.pfx) or its associated password may be invalid.
   b. The public key or self-signed certificate file has not been uploaded to Azure AD.
Solution:
1. Validate Credentials:
  1. Ensure that the Tenant ID, Application ID, and Secret Key entered are correct.
  2. Refer to the Vembu BDR help document to verify that the required API permissions have been correctly assigned to the application.
2. Clock Synchronization:
  1.  Confirm that the system clock on the backup server is synchronized with internet time. If not, synchronize the system clock.
3. SSL Certificate Verification (Applicable if Application Certificate is chosen):
  1. a. Ensure that the provided .pfx file and its associated password are valid.
  2. b. Verify that a Public Key or Self-Signed Certificate file has been uploaded to Azure AD. If not, follow these steps:
    1. Sign in to the Azure Portal using your Microsoft 365 Organization admin account.
    2. Locate the Azure Active Directory.
    3. Navigate to Registered Azure App for the BDR server.
    4. Select "Certificates & secrets."
    5. Click "Upload certificate" and select the appropriate certificate file (.cer, .pem, .crt) for uploading.
This knowledge base article provides guidance on resolving the issue of being unable to connect to the Microsoft 365 Organization when using Vembu-Backup-for-Microsoft-Office-365-Cloud and Vembu-Backup-for-Microsoft-Office-365-On-Premises products.