On S3 uploads with the location Frankfurt, I get. The authorization mechanism you have provided is not supported. Please use AWS4-HMAC-SHA256. So I have searched and I see the reason. I just wish to ask if Fine Uploader using S3 scipts has a solution please? As it is the only bucket region that I am having problems with.
Fine Uploader S3 does not yet support v4 signatures, so you will need to avoid using new regions at the moment. However, the 5.3 version of Fine Uploader will support v4 signatures (5.2) is currently in development.
This is our highest priority for the 5.3 release. Please see case #1336 for updates and more details.
Update: Support for version 4 signatures was added to Fine Uploader 5.4.0.