After I made certain changes to the UI and committed or pushed it to GitHub, I came across this list of errors that did not appear in my previous compilations while I was coding. After some debugging, I was able to fix the issue by deleting and replacing the same exact widget blueprints that were within the "larger" widget blueprint. Since I could not identify the underlying reasons for this "bug," I decided to take note of this anomaly in case I encounter another similar issue.

Since "Attempted to access missing property" is a very common and straightforward error, I want to focus on the other error stating "If this is a packaged or cooked build. Are you attempting to use an editor-only property?" This error is very weird in the sense that my game was not a "packaged or cooked build," or at least it shouldn't be anything other than the default build. It worked in my previous compilations, so why throw the error after I committed to GitHub?

In my case, my main menu, "WB_MainMenu," includes two sub-menus, "WB_HomeMenu" and "WB_AdvancedMenu." So I had to delete the two components and add them back to the widget switcher. Thank goodness all the references still worked, so I didn't need to reconnect all the nodes and recreate all the logic.