In Android Studio, my cursor is white rectangle. I'm cannot write anything. And changed my keyboard button actions.
h-->left arrow j-->down arrow k--> up arrow l-->right arrow
How can I fix problem or can I reset Android Studio settings?
Just got the same problem as yours. And this is the solution:
Go to File > Settings > Editor > General > Appearance, then uncheck the Use block caret
Try fn + ins. That worked for me.
Press Fn + Del on your keyboard together. Explanation: Its because Delete key on keyboard has Insert function. So pressing Del along with Fn key will enable Insert mode within your editor from Overwrite mode as in your case.
It's ins in the latest version of Android Studio.
Just restart Android Studio and voilà !
None of the other solutions worked for me (Windows 7, maybe with an inactive Lock Num key).
fn + insert it will work.
And if it not work then try Go to File > Settings > Editor > General > Appearance
Try fn and insert keys together it will work.
来源：https://stackoverflow.com/questions/28606348/close-white-cursor-in-android-studio