macuco's suggestion worked for me.
I'm running a MacBook Pro with OS Mojave 10.14.2 using the USB cable (with a USB-C) adapter into my newish POD HD Pro X.
I went to System Preferences and selected Security & Privacy on the top row of icons
I then selected the General tab.
I unlocked the lock icon to make changes.
Down where it says "Allow apps downloaded from" I had the message "Line 6 Monkey is blocked something something". I clicked the Allow button next to it.
I restarted my laptop. When I brought everything back up, I was able to connect to the POD HD Pro X, update the drivers, Flash Memory and USB Firmware.
I was also able to successfully connect the Pod HD Pro X Edit software to the unit and download the presets.
My Photoshop skills are only slightly worse than my guitar playing, but here's a screenshot of the Security & Privacy screen with an arrow showing where to look for the message about allowing Line 6 Monkey to work. (The message isn't there because I'd already hit the Allow button).