Handle errors for Cloud Storage for Unity

Sometimes when you're building an app, things don't go as planned and an error occurs.

When in doubt, check the error returned, and see what the error message says.

Note: By default, a Cloud Storage for Firebase bucket requires Firebase Authentication to perform any action on the bucket's data or files. You can change your Firebase Security Rules for Cloud Storage to allow unauthenticated access for specific situations. However, for most situations, we strongly recommend restricting access and setting up robust security rules (especially for production apps). Note that if you use Google App Engine and have a default Cloud Storage bucket with a name format of *.appspot.com, you may need to consider how your security rules impact access to App Engine files.

If you've checked the error message and have Cloud Storage Security Rules that allow your action, but are still struggling to fix the error, visit our Support page and let us know how we can help.

Handle Error Messages

There are a number of reasons why errors may occur, including the file not existing, the user not having permission to access the desired file, or the user cancelling the file upload.

To properly diagnose the issue and handle the error, here is a full list of all the Firebase.Storage.StorageException errors our client will raise, and how they can occur.

Name	Reason
ErrorUnknown	An unknown error occurred.
ErrorObjectNotFound	No object exists at the specified reference.
ErrorBucketNotFound	No bucket is configured for Cloud Storage.
ErrorProjectNotFound	No project is configured for Cloud Storage.
ErrorQuotaExceeded	Quota on your Cloud Storage bucket has been exceeded. If you're on the Spark pricing plan, consider upgrading to the pay-as-you-go Blaze pricing plan. If you're already on the Blaze pricing plan, reach out to Firebase Support. Important: Starting October 1, 2025, the Blaze pricing plan will be required to use Cloud Storage, even default buckets.
ErrorNotAuthenticated	User is unauthenticated. Authenticate and try again.
ErrorNotAuthorized	User is not authorized to perform the requested action. Check your rules to ensure they are correct.
ErrorRetryLimitExceeded	The maximum time limit on an operation (upload, download, delete, etc.) has been exceeded. Try uploading again.
ErrorInvalidChecksum	File on the client does not match the checksum of the file received by the server. Try uploading again.
ErrorCanceled	User canceled the operation.