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B2 Cloud Storage

Backblaze B2 Access Denied Error

Diagnose bucket and object permissions.

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Before you begin

Check whether you are using Backblaze Computer Backup or Backblaze B2 Cloud Storage. The two products have different setup, billing, and recovery procedures. Confirm your operating system, software version, and the exact error before changing settings.

Steps to follow

  1. Identify the denied API operation.
  2. Check the application key's allowed capabilities.
  3. Verify bucket restrictions and file prefixes.
  4. Avoid switching to a master key merely to bypass permissions.

How to confirm the fix

Repeat the affected task using a safe test. For Computer Backup, check that new files are being backed up and that an appropriate restore point is available. For B2, test a limited upload or download using the intended scoped credentials. A successful status message is not a substitute for a tested restore.

If the issue continues

Record the exact error, time, product, client version, and relevant non-sensitive logs. Consult the official Backblaze Help Center for current instructions. Do not remove the only backup copy, weaken access controls, or disable retention rules just to dismiss a warning.

Security: Never send your account password, two-factor code, private encryption passphrase, B2 application key, or backed-up files through an independent callback form.

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