This issue only affects ZCB with Amazon S3. All versions of ZCB with Amazon S3 are affected.
A workaround for this issue is included in ZCB version 4.10. Please upgrade if you have not done so already.
What's going on?
Uploads with ZCB are done in "chunks", and a new connection to Amazon S3 is made each time a new chunk is ready to upload.
We hope that Amazon resolves this issue soon. Once resolved, the changes made to the hosts file should be undone.
Please create a support case if you'd like to be notified when the issue has been resolved.