Hi @emu 

Good questions.

Help articles for AWS S3 Zap app: https://zapier.com/apps/amazon-s3/help

I Can't Add to a Specific Bucket (400 error)

Is your bucket in a different region than the one you selected when connecting your S3 account to Zapier? If so, you will need to reconnect and select the matching region.

Note that often (depending on the security policy of the S3 account you have connected to Zapier), we are able to see buckets from regions other than the selected region, but we are not able to interact with them. For example, if you have a bucket in US East (Ohio) (which is us-east-2), you may be able to select that bucket in a drop-down, but if you selected us-east-1 when you connected your account, we won't be able to upload files to that bucket.

AWS has documentation on their region names here if you aren't sure which numerical region your bucket resides in: https://docs.aws.amazon.com/general/latest/gr/rande.html#s3_region

If you are still having trouble after this, please drop us an email so we can troubleshoot further with you!