Select a Backblaze B2 bucket, click right and select "Duplicate". Enter the name of the new bucket. The files will start to be copied. The majority of the time, however, a partial copy will be made and then an error "Cannot create folder . Bucket name is already in use. Please contact your web hosting provider for assistance."
In the log (attached), I see a several list POSTs, a create bucket, and a copy file. It then attempts to post another create bucket command, which returns a HTTP 400, then closes.
When I refresh the window, the new bucket and at least one new folder/file has been copied, but not all.
This doesn't happen all of the time. It could potentially be related to transferring "large" files, but no way to explore that any further. Edit to the "large" files comment. I am about 10% through duplicating a folder with a lot of "small" files (<25MB) and it seems to be working OK. We'll see if it finishes. So I suggest that perhaps the problem is related to transferring larger files (hundreds of MB in size).