I have a simple two node UCM 22.214.171.12400-18 setup.
I've configured DR in the usual way, storeage location created successfully. Free FTPd is the SFTP server I'm using.
When I start a manual backup, everything goes well until the 60% mark and then the process stops dead with the following error:
"ERROR: unknown platform error, backup completed..."
The process seems to stop after backing up the Publisher and immediately on commencing backup of the subscriber - see the screenshot.
I've had problems with DR in UCM v5 but I thought these had all been resolved in later versions of and in version 6.
Latest version, latest problem!