When I read about the very promising Harmadillo algorithm I immediately tried starting my H9 control app (3.5.4 at the time) on Windows for the first time after updating the OS to the Windows 10 May 2019 Update (Build 1903).

H9 Control App starts but then never shows the dialog box to switch to Demo mode and in the Main Window  then indefinitely just shows a rotating wheel ('not responding' in title bar) until I kill the process using Task Manager. Next I tried with an H9 connected, but the problem persisted.

Then updated from 3.5.4 to 3.6.0., but the issue remained the same. Updated the H9 firmware  successfully using my Android phone, but reconnecting the upgraded stompbox to Windows H9 Control still will not start up. Anyone else having this issue?

Dear Eventide Team, please urgently check H9 Control's compatibility with Win 10 Build 1903 and provide a fix.

Does your PC have any MIDI devices connected? If so, could you remove them and then try openning the latest H9 Control?