Are you using the same USB to TTL serial adapter (AKA "FTDI") on both the working and non-working Pro Mini? Do you connect it exactly the same on both Pro Minis?
Sketch uses 444 bytes (1%) of program storage space. Maximum is 30720 bytes.Global variables use 9 bytes (0%) of dynamic memory, leaving 2039 bytes for local variables. Maximum is 2048 bytes.