Tried last 2 versions of the winbm.iso, after successfully booting from it and wizard launching if fails at step 2 of 4: "Select source for restore". After entering the UEB IP address and providing credentials wizard fails with an error message: " ... Form that is already visible cannot be displayed as a modal dialog box ... The wizard will now close".
If you enter an IP address as the "Backup Source", then move out of that drop down box by clicking somewhere else on the dialog, you will get the error after entering the username/IP. If instead, after entering the IP address as the "Backup Source", you tab out of the drop down box, you do not get the error.