PhpStorm or IntelliJ suddenly hangs / freezes / keyboard not responsive/ unresponsive while editing in Linux / Ubuntu

Problem

The symptom is that while editing the IDE freezes, somehow the keyboard no longer responds. Two years ago at Tweakers there was luckily someone using Ubuntu who could tell me right away how to fix it ("Just killall -9 ibus-x11", and it would magically continue to work). Now more recently at AutoTrack--where I now work--a collegue encountered the same issue. Luckily I knew the fix this time.

The fact that I personally know at least five different individuals who spent time fixing this makes me guess there are a lot more people still. Hence this blogpost with some keywords that will hopefully lure others into this fix...

Fix

According to this bug report:

killall -HUP ibus-daemon

Or use this one:

killall -9 ibus-x11

I have no idea what ibus exactly is, and I don't really care Also it may be possible to just uninstall ibus, I didn't try this, but I can imagine the following to work..

sudo apt-get remove ibus