Scaler Causes Sustain/Hung Note in Logic Pro X

Hi there,

From time to time, Scaler will cause a certain note (usually E) to sustain/hang in Logic Pro X (particularly when using musical typing). When I turn off Scaler as a MIDI FX and press the same key (e.g., E) that causes the sustain, it does not sustain so the issue seems to be tied to Scalar. In Logic, I have tried to troubleshoot the issue by bypassing all control surfaces, yet the note still sustains. Please advise.

Thank you in advance for your reply.

Logic Pro X 10.4
Scalar 1.6.1
Mac High Sierra

Hi @sfgiants,

we are aware of some issues with hung notes.
You can use the “Midi Panic” button at the top of Scaler UI, it’s a small button with an exclamation mark “!”. When clicked, it sends a global note-off message and clear any hung notes on the UI as well.

We are working on improving the internal midi processing to prevent notes from getting stuck in the first place.

Thanks for reporting your issue and supporting Scaler,


It’s doing the same in Cubase latest version (10.5) :frowning: