Android - Google keyboard (gboard) keeps crashing, won't go away

It's very easy - just follow the instructions below:

Open Settings/App Management/Gboard/Storage;

Then clear up the cache and you are good to go! If it does not work even after this step, you have to follow the exact same instructions but instead of clearing cache you clear data. That is a sure shot method to get it to work, but I do not recommend it before you clear cache as when you clear data your preferences are reset.

Ok I have just fixed this on my Motorola phone (the problem has just recurred very widely this December 2019). I believe an update has been rolled out to solve the problem so the issue is, how to get your gboard updated if it hasn't happened automatically.

"Gboard stopped working" kept popping up on my screen while following through on the process below, so I had to keep selecting "ok" every time it popped up, giving me small windows in which to perform the necessary actions.

Go to the Play Store, search for Gboard (SEE BELOW) and identify the app (which had its icon next to the word in the search options that came up for me) and select it. You should then have the option to update the app. Select update. After the installation finished everything was working again for me.

IMPORTANT To enter Gboard into the search bar you cannot use the keyboard. So select the microphone at the right-hand end of the search bar and speak, "Gboard" - i.e. use voice to text.

Having solved this problem, I can affirm the answer given by Jinen Setpal. Not having 50 reputation, I can't make a comment, so I'm saying this as a separate answer.

When I had this problem, not every button was responsive (even if there was a slight cue in the UI that it had been pressed). This prevented me from simply clearing the cache for Gboard, so I had to clear the data (I think it was around 60mb, then it went to about 40 something kb). Just as Jinen Setpal noted, there was a confirmation popup that warned that all of the data for that app would be deleted, even from databases (meaning that there is no backup for it).