Lenovo A2010-a keyboard I updated my lenovo A2010-a system and I can't unlock it cause my password is a pass code type, and the keyboard isn't working.
I already tried restarting my phone many times.
What should i do?
Have you tried the following fixes:


Fix 1: Restart the keyboard


Restarting the keyboard can be very effective in solving the problem. Many have found this to be helpful. 


Go to the Settings menu of the device
Scroll down to the Apps section and Tap on Application Manager
Swipe to go to the “All” tab
Now look for the app Android Keyboard and tap on it
Now tap on Force Stop to stop the keyboard


Exit out of the Settings menu and go back to using the keyboard and check if it works. If you happen to use a third party keyboard or if the device manufacturer has installed its own keyboard then you should look for the keyboard that is in use.


Fix 2: Clear Cache and Data for Keyboard


Clearing the cache and data of an application allows you to clear files that can be possibly corrupted or which may be creating problems because of bugs.

While deleting the cache files does not delete any important information, you will lose your personal settings when you delete the data files from any app. 

If you had made specific changes to the keyboard, you will lose those settings. You will have to go back into the keyboard settings and make the changes once again.


Go to the Settings menu of your device
Tap on Application Manager which is under the apps section
Swipe to the tab which includes “All” apps
Now look for the keyboard app. It can be Android Keyboard or the keyboard that you are using if you have installed a third-party      keyboard or if you have the manufacturer skin on top of the stock       Android.
Tap on the keyboard app
Tap on Clear Cache
Now tap on Clear Data
Tap on OK to confirm.


Fix 3:  Clear Cache and Data Files for Dictionary App



The dictionary app is closely linked with the keyboard app.

If for any reason you get the “unfortunately keyboard has stopped” error, there is a chance that it may be because of corrupt files in the dictionary app. 
Deleting these files can be helpful in solving the problem.


Go to the Settings menu of your device
Tap on Applications Manager
Swipe to go to the “All” tab
Scroll and look for Dictionary app and tap on it
Tap on Clear Cache
Tap on Clear Data
Tap on OK to confirm


Once the cache and data files have been deleted, check if the problem has been fixed.


Fix 4: Install Updates for Google Keyboard

You can try fixing this issue by installing updates for Google keyboard. For that, navigate to play store on your android phone and look for the updates. Alternatively download the updated Google keyboard from google play store via your PC (Apk leecher website - can directly download the apk from Google play servers) 


Acknowledgements:
Fix Android keyboard stopped working