Connection test failing

4 min readUpdated June 28, 2026

If the connection test in WP Media Cloud settings is failing, the plugin cannot reach your storage bucket. No files can be offloaded until the connection test passes. Work through the checks below for your storage provider.

Run the health check first#

Go to Media Cloud > Health and run the health check. The health check shows separate results for API connectivity, storage credentials, upload test, and CDN ping. This tells you exactly which part of the connection is failing and gives you a starting point for diagnosis.

Check 1: Credentials are correct and complete#

The most common cause of a failed connection test is a credential error — a wrong value, a missing field, or an accidental trailing space. Copy credentials directly from your provider’s dashboard rather than retyping them.

Provider-specific things to double-check:

Bunny Edge Storage — the Storage Zone Password is not the same as your account API key. The password is found in the FTP & API Access tab of your specific storage zone, not in your account settings.
Cloudflare R2 — the Access Key ID and Secret Access Key come from an R2 API token, not your Cloudflare account API token. The secret is only shown once at creation — if it was lost, create a new token.
Amazon S3 — the IAM user must have s3:PutObject, s3:GetObject, s3:DeleteObject, and s3:ListBucket permissions on the correct bucket ARN. Check the IAM policy in the AWS console.
Backblaze B2 — the Access Key field takes the keyID value and the Secret Key field takes the applicationKey value. These names are different from the standard access/secret pattern used by other providers.
Google Cloud Storage — WP Media Cloud uses HMAC credentials from the Interoperability tab in Cloud Storage settings, not a JSON service account key file.

Check 2: Bucket name and region are correct#

Bucket names are case-sensitive on all providers. A single character difference will cause the connection to fail with a bucket not found error. Confirm the bucket name in your provider’s dashboard matches exactly what is entered in WP Media Cloud settings.

Region codes must also match the bucket’s actual region. Each provider has its own region code format:

Amazon S3: us-east-1, eu-west-1, ap-southeast-1, and so on
Wasabi: same format as AWS — us-east-1, eu-central-1, and so on
DigitalOcean Spaces: nyc3, ams3, fra1, sgp1, and so on
Hetzner: fsn1, nbg1, or hel1
Backblaze B2: the region is the middle segment of the S3 endpoint URL — for example us-west-004 from s3.us-west-004.backblazeb2.com

Check 3: Endpoint URL format (S3-compatible providers)#

For the S3-compatible endpoint option and some named providers, an incorrect endpoint URL format is a common failure point. The endpoint URL must include the https:// prefix. It should not include the bucket name or a trailing slash.

If the connection test returns a path-style or virtual-host error, toggle the Path-Style URLs setting in the S3-compatible endpoint configuration. Some providers require path-style URLs; others require virtual-hosted style. Try both if unsure.

Check 4: Outbound connections from your server#

WP Media Cloud uploads files from your server to the storage provider. If your server cannot make outbound HTTPS connections to the provider’s endpoint, every upload will fail. The connection test may time out or return a network error rather than an authentication error in this case.

Signs that outbound connections are blocked:

The connection test times out with no response rather than returning an error message from the provider
The Health tab shows the upload test as failed for all providers, not just yours
PHP functions like curl or file_get_contents return network errors when tested with external URLs

Contact your hosting provider and ask them to confirm that your server can make outbound HTTPS requests to your storage provider’s endpoint URL on port 443.

Check 5: Bucket permissions#

On some providers, a bucket can be reached but the API key or IAM user does not have write permissions. The connection test may succeed (confirming the bucket exists) but offloading fails because the credentials can read but not write.

Confirm the API key or IAM user has both read and write permissions:

Amazon S3: IAM policy must include s3:PutObject on the bucket ARN
Cloudflare R2: API token must have Object Read and Write permissions on the bucket
Wasabi: access key must have read and write access to the bucket
Backblaze B2: application key must be set to Read and Write for the specific bucket

Check 6: SSL certificate issues#

If your site has an SSL certificate problem — a self-signed certificate, a certificate that does not cover your domain, or an expired certificate — some hosting environments will refuse outbound HTTPS connections from the server to external providers. This manifests as a connection test failure with an SSL or certificate error message.

This is most common on local development environments and staging sites. Ensure your site’s SSL certificate is valid before testing cloud storage connections in those environments.