This is using the most up to date release (1.2.437) as well I just tried compiling a version based on the latest commits with the same outcome. When trying to clone a MBR partition from a .img file to ...
The MBR data printed in the debug information does not match this data. "Invalid MBR" is only printed if the boot signature was not found, and the debug information shows a different start (504d...) ...