Hi David,I will test this on my end also but some times an OS version update will introduce "ghost" HID's, especially keyboards or trackpads, that can be opened but do not generate data. This has happened a few times before. The way to check is to change the kbNum and see if using a different number (1, 2, 3, etc.) produce data. You only need to try this until you see "couldn't open keyboard #" for whichever number after 0, which means you've exhausted the list of things ChucK thinks is a keyboard.Otherwise this could be a new issue specific to El Capitan :(spencerOn Wed, Oct 28, 2015 at 11:16 AM, David Loberg Code <d.loberg.code@wmich.edu> wrote:I have a student with a MacBook Pro (Retina, 13", early-2015). She was on Yosemite with latest ChucK build; now on El Capitan with the ChucK beta build (1.3.5.2 beta). The same problem happened in both builds.She can open the keyboard with Hid. It will successfully pull the kb.name and print it.However, it won’t detect any other activity from the keyboard.It gets stopped at kb=>now; and won’t go any further. We have tried an external USB keyboard too, and it produces the same problem.Anyone else have this happen OR have a cure?thanks,davdHid kb;HidMsg kbMsg;0 => int kbNum;kb.openKeyboard( kbNum ) => int kbAvailable;if ( kbAvailable == 0 ) me.exit();while (true) {// hangs up waiting for kb=>now eventkb => now;while(kb.recv(kbMsg)) {if (kbMsg.isButtonDown()) {kbMsg.key => int keyNum;<<< "#", keyNum >>>;} //end button down} // end while hid.recv} // end while(true)