Solved: You need to use a Theme.AppCompat theme (or descendant) with this activity

One of those types of annoying errors that'll have you do a lot of work for something that's actually a 2 second job and no real effort.

If you find yourself with an app that crashes with no output, open logcat from visual studio and you'll notice that around the time of our app crash, there's a lot that states 'You need to use a Theme.AppCompat theme (or descendant) with this activity'. At first you'll start to look into the application and where you might change the theme, but in reality, if we go down that route, it could end up changing your entire app look and feel, something which will take a long time to put back to normal.

It turns out that the fix for this issue is actually to clean the Android solution and run again as normal, this will solve the crash and your error will disappear from logcat.

If you run into any issues after cleaning and running where this error is still present, comment below.

My particular setup when I got this error was as follows:

Minimum Android Version: 4.2 (API 17 - Jelly Bean)

Target Android Version: 7.0 (API 24 - Nougat)