Error Reference

Fil One returns standard S3 error responses in XML format. If your application already handles S3 errors, no changes are needed.

Error response format

<?xml version="1.0" encoding="UTF-8"?>
<Error>
  <Code>NoSuchBucket</Code>
  <Message>The specified bucket does not exist.</Message>
  <BucketName>my-bucket</BucketName>
  <RequestId>abc123def456</RequestId>
</Error>

Common error codes

Client errors (4xx)

Code	HTTP Status	Description
AccessDenied	403	You do not have permission, or the object is protected by Object Lock.
BucketAlreadyExists	409	The bucket name is already taken.
BucketNotEmpty	409	The bucket contains objects with active Compliance retention and cannot be deleted.
InvalidAccessKeyId	403	The access key does not exist or has been revoked.
InvalidBucketName	400	The bucket name does not meet naming requirements.
InvalidArgument	400	A request parameter is invalid.
InvalidObjectState	403	The operation is not valid for the object's current state (e.g., locked).
NoSuchBucket	404	The specified bucket does not exist.
NoSuchKey	404	The specified object does not exist.
SignatureDoesNotMatch	403	The request signature does not match. Check your secret key and signing method.
TooManyBuckets	400	You have reached the maximum number of buckets.

Server errors (5xx)

Code	HTTP Status	Description
InternalError	500	An internal error occurred. Retry the request.
ServiceUnavailable	503	The service is temporarily unavailable. Check the Retry-After header.
SlowDown	503	You are sending requests too quickly. Implement exponential backoff.

Object Lock specific errors

Scenario	Error code	HTTP Status	Meaning
Delete locked object	AccessDenied	403	Object has active Compliance retention. Error message includes the expiry date.
Shorten retention	AccessDenied	403	Compliance mode retention cannot be shortened. You can only extend it.
Delete bucket with locked objects	BucketNotEmpty	409	Bucket contains objects with active retention. Error includes count and earliest expiry.
Disable Object Lock	InvalidBucketState	409	Object Lock is always enabled and cannot be disabled.
Suspend versioning	InvalidBucketState	409	Versioning is always enabled and cannot be suspended.

Troubleshooting

SignatureDoesNotMatch -- The most common auth error. Check that:

1. Your secret key is correct (re-copy from the dashboard if unsure).
2. Your system clock is accurate (SigV4 requires clocks within 15 minutes of server time).
3. You are using the correct region (eu-west-1).

AccessDenied on delete -- If you are trying to delete an object and getting 403, check whether the object has active Object Lock retention with GetObjectRetention.

ServiceUnavailable (503) -- Transient. Retry with exponential backoff. If persistent, check status.fil.one.