This error is because you have another device trying to access the same MIDI port as you have set in MIDIBuddy. It does not close because it keeps trying. The easiest way to fix this is to ensure there are no other MIDI programs open that may be trying to access the MIDI Port you have set it MIDIBuddy for communicating with Bome MIDI Translator. On Windows, many DAWS and other application may try to open all available MIDI ports. If they, for instance open BMT 1 and you are also using that for MIDIBuddy, then MIDIBuddy will no longer have access to that port… Most of the time this can be fixed by either closing the offending application or setting it up so that it doesn’t try to open the port you have set in MIDIBuddy.
There are occasions when moving MIDI devices around that the MIDI port configuration will change. To fix this, close all MIDI based applications. Open MIDIBuddy and go to settings in the menu tray to re-establish the correct MIDI port you want to use to communicate with Bome MIDI Translator Pro.
Then when you open MT Pro and MIDIBuddy, they should be able to talk throught the newly established port.
Let me know if this helps