App crash on click of Device Home Button after adding tag while creating new task.

Expected behavior

Tasks app allows users to assign tags to their task while creating new task. Excepted behaviour from app is while creating a new task, i assigned some tags to my task and now if without saving if i click on my device 'Home Button' then the app needs to be go to background not crash.

Actual behavior

While creating a new task i fill the details of my task, then i came to a section where i can categorise my task by adding tags. So i add a tag and then without saving my task, i clicked on my device 'Home Button' and app got crashed.

How to reproduce

To reproduce the bug follow the following steps :-

• Open app and click on '+' icon to create a new task.
• Now you have a screen where you can add details of your task.
• Now you see a field name 'Uncategorized', click on the field. A pop up will open with 'create a new tag field'. Enter anything in the field and press anywhere on your screen to close the popup.
• Now your tag is created. Just press the 'Home Button' of your device and you will see the app got crashed.

* Device:  Samsung J7 Prime
* Operating system: Android 7.0 Nougatt
* App Version: v5.3.4

Recording Of The Bug