We’ve spent the last days investigating the recent Windows Update MIDI issues in depth, especially the problems affecting virtual MIDI ports like LoopMIDI.
After extensive testing we can confirm that the behavior is caused by changes in the new Windows MIDI Services stack which Microsoft is currently rolling out with Windows 11 updates. The new MIDI subsystem introduces a different device discovery mechanism and changes how virtual MIDI endpoints are handled.
As a result, some virtual MIDI drivers (including LoopMIDI / teVirtualMIDI-based ports) may currently show issues such as:
• ports not appearing in applications
• ports appearing with different names
• ports disappearing after reboot
• ports not being detected until the MIDI service restarts
This is not a MetaGrid issue, but rather a compatibility problem caused by the transition to the new Windows MIDI architecture.
The good news is that Microsoft’s new MIDI stack also introduces native routing and virtual endpoint capabilities, which will eventually replace the need for third-party loopback drivers.
Because of this shift, we are already planning the migration of our Windows integration toward the new native Windows MIDI system to ensure long-term stability and compatibility with upcoming Windows updates.
We will share more details as this work progresses.
In the meantime, if you encounter issues with virtual MIDI ports, restarting the Windows MIDI Service or reducing the number of virtual ports can sometimes temporarily restore functionality.
Thanks to everyone who reported the issue and helped us track this down.