GarageBand and PreSonus AudioBox Usb

Gilbert Solorio wrote:

my Audiobox USB is no longer being recognized by GarageBand [...] Is this related to the latest OS?

very likely.

there are new security settings in the latest OS that prevent apps from using input devices; check the security settings in System Prefs and make sure that GB has permission to use your interface.

here's a screen shot from another user showing permission being given to the internal mic:

Gilbert Solorio wrote:

I do have an audio-OUT from the keyboard and have it plugged into the line-IN on the interface (backside side).

this is the interface you'r using, correct?

https://www.presonus.com/products/AudioBox-USB

if so, there is no line-IN on the interface's back side, only a phone-OUT, and L/R main-OUTs:

Gilbert Solorio wrote:

I also have another cable from the keyboard (Line Out R/R+L) to the front of the interface.

that's the cable you need to send audio from the keyboard to the interface

do you see the same behavior in System Settings-> Sound->Input?

seems like contacting PreSonus support and providing all the information you have might be the best bet.

what you described really sounds like a bad cable, but since you tried another cable and still saw the same behavior... two bad cables isn't likely. maybe PreSonus will have an idea.

is there any chance the MIDI cables got mixed up (i.e. accidentally set up as IN to IN instead of OUT to IN on the interface) while you were troubleshooting?

(Side note: GB doesn't support MIDI-OUT, so you don't need the MIDI-IN cable on the keyboard)

those pics are pretty tiny, but it looks like you also took an audio-OUT from the keyboard and plugged that into the line-IN on the interface. are you able to record the keyboard's sounds on an audio track?

the cabling all looks good in these shots.

a software track shows no indication of receiving a MIDI signal... what happens on an audio track, any signal from the keyboard's line-OUT showing?

is the AudioBox selected in GB's prefs for audio input?

in System Prefs->Sound->Input, if you select your interface do you see any level when you play the keyboard?

if it's a driver incompatibility, you'll need to contact PreSonus to see if their latest driver is compatible with the latest version of macOS

i just took a look and saw that they do claim support for macOS 10.14

off hand the only other thought that comes to mind is to try a different USB cable

Gilbert Solorio wrote:

no sound is being recorded or recognized when I select Software Instrument and select piano.

which make/model MIDI keyboard are you using?