Fine Uploader getting “Policy expired” message sending to S3 for some

Question

I recently implemented Fine Uploader and it\'s been mostly successful. A few users are however are not able to upload. They are all using modern browsers (IE10, FF and Chr

Answer 1

The timezone settings will have no effect as times are UTC. However, if the time on the user's computer is not accurate (say, off by 5 or more minutes), then the policy will be expired, according to Amazon.

Fine Uploader sets an expiration date to 5 minutes (again, in UTC). The date used is generated in the browser, so your client machine's time will be used. If the client machine's clock is slow by 5 or more minutes, the policy will be seen as expired when Amazon handles it.

I'm fairly sure that the issue is due to a significant drift on your customer's machine clock. If you verify this, I suggest you instruct them to keep system clock synced with a time server.

Update: A new feature was added to Fine Uploader 5.5 that allows you to overcome extreme clock drift on user machines/browsers. See the clock drift section on the S3 feature page for more information.