Invalid choice of displayId

[abrobston]

When I try to use the Screen Capture menu item, I get a window with the error message:

Error: Invalid choice of displayId: 3 (valid choice is an integer between 0 and 2)

If I try to debug, I can get this stack trace:

(anonymous) (index.js:21)
performScreenCapture (index.js:11)
(anonymous) (index.js:64)
Promise.then (async)
darwinSnapshot (index.js:64)
(anonymous) (index.js:284)
exports.default (index.js:289)
processTicksAndRejections (internal/process/task_queues.js:86)
await in processTicksAndRejections (async)
(anonymous) (capture.js:277)
await in (anonymous) (async)
run (capture.js:195)
runCapture (app.js:128)
click (app.js:254)
MenuItem.click (menu-item.js:56)
executeCommand (menu.js:31)

I'm using Duet Display to add an iPad as a display, and that display was not present on startup. Indeed, inspecting the displays array shows that the iPad is not in the array. However, quitting and starting MagicCap doesn't fix the issue. Incidentally, I'm not even trying to capture on the iPad; I get that error on one of the other screens.

If I run system_profiler SPDisplaysDataType at the command line (as I believe the listDisplays() function essentially does), there is no mention of the iPad display, Duet Display, etc. So, while there might be an OS issue at play here, perhaps a workaround of some kind is in order?

Expected behavior is, of course, to allow me to select the screen region.

System is OS X Catalina 10.15.6. MagicCap version is 2.1.2.