Recently I have updated my Samsung GT I-9300 from cyanogen mod 11 snapshot M8 to snapshot M9. After update keyboard was not showing when clicked on any input box. After some research I’ve found, that clearing keyboard app (touch input, AOSP keyboard, Samsung keyboard…) data should fix this. But it didn’t help.
After few moments I was looking into input settings and noticed, there is not selected default keyboard.
So you need to select your default keyboard input.
After that the keyboard should popup with no problems.
Update 1: Bug came back even after this fix, could fix it even with full reformat. I have migrated to SlimROM and everything works as expected.