How to show Android Studio's Messages Window?

Question

When I build a project and there are errors, the Messages window that shows all the errors does not always show. I have to build the project (i.e. Ctrl + F9

Answer 1

I got here after upgrading to Android Studio 3.1, in which they removed the Messages window, replacing it with the Build window. After some poking around, I found this button on the left side of the Build window:

Clicking this button toggles the view between the new "Build" view and the old "Messages" view.

I hope this helps someone who has the same problem!

UPDATE: per suggestions in the comments, since this doesn't really answer the asked question, I opened it up as its own question: Where is the Messages Window in Android Studio 3.1

UPDATE 2: In Android Studio 3.3 the button now looks like this:

UPDATE 3: In Android Studio 3.6 the button is gone. Instead, the build window is permanently split between text output and visual output. If you can't find the text output, it might be fully collapsed, so look on the top right of the build window for something like this:

And try to drag it left to reveal the build window, like this:

Hope this helps!