iTunes crash causes Adobe Indesign crash

For no apparent reason, iTunes will stop responding (rainbow pinwheel). Then, when I navigate from iTunes to Adobe Indesign (CC 2018), Indesign also freezes up. Note that Indesign runs just fine until I navigate to a frozen iTunes.

Additionally, neither of them will Force Quit. I have attempted all forms of Force Quit operations, from keyboard shortcuts to Activity Monitor to Terminal. The processes will successfully disappear from the list in Activity Monitor, but the applications will fail to reload. Furthermore still, I cannot shut down or restart the computer because the processes are still active. I can only hold down the power button for the force the computer to turn off and reboot.

I have tried complete uninstalls and reinstalls of both applications, and this has not resolved the issue.

Is anybody else experiencing this?