Forum Discussion
MIDI sysex message transmit fails after installing Security Update KB5077181
In the widely used MIDI application MIDI OX, I can no longer transmit MIDI sysex messages to a MIDI output port. Connecting a MIDI input in the app to a MIDI output echoes MIDI channel messages normally. Sysex messages do not appear in the output window and are not sent to the MIDI output port. Also, attempting to send a sysex message from within the app results in the error message "SysEx: No Buffers Available".
I was able to repoduce this with two USB MIDI interfaces: M-Audio Midisport 4x4, and MOTU Midi Express 128.
Uninstalling Security Update KB5077181 restores expected functionality.
This is on Windows 11 Pro.
LInk to my feedback hub report on this issue:
https://aka.ms/AAzwx9y
2 Replies
The KB5077181 update appears to interfere with MIDI SysEx transmission in applications like MIDI-OX. Error messages such as "SysEx: No Buffers Available" indicate problems with buffer allocation or driver communication. The problem affects multiple USB MIDI interfaces, confirming it's not device-specific.
Microsoft may release a fix or workaround in subsequent updates addressing this compatibility problem. Ensure your Windows is current, and monitor Windows Update for patches.
