To start, I want to say since this is UA content I do not expect a fix. This is simply to let the Devs know that an error exists. Basically, non-text numbers cannot appear in the Distance field, and there's no way to display "Unlimited" without going to the sidebar. Entering a negative number in a Sense field immediately crashes the character sheet.

Class: Cleric

Subclass: Twilight Domain (UA)

Class Feature: Eyes of Night

Your eyes are blessed, allowing you to see through the deepest gloom. You have darkvision with no maximum range; you can see in dim light as if it were bright light and in darkness as if it were dim light.You can magically give the benefit of darkvision with no maximum range to any number of creatures you can see within 10 feet of you. The shared benefit lasts for 10 minutes.You can extend this benefit 3 time(s), and you regain all expended uses when you finish a long rest.

Steps to Reproduce:

1. Observe "Senses" section of character sheet, note that "Darkvision" is not listed.
2. Click "Customize Senses", scroll to Darkvision customization.
3. Attempt to enter "Unlimited" in "Distance" field. Field does not accept non-numerical characters.
4. Click down arrow on "Distance" field, which enters "-1". Contemplate absurdity of negative vision (Can they only see behind them?)
5. Character sheet crashes (error code 81b0bd0f4b7545a7b1aca761c5126d53)
6. Re-load character sheet, back to "Customize Senses" menu.
7. Enter "Unlimited" in 'Source/Notes" field. Text saves, but does not appear on character sheet.
8. Enter "Class Feature" in "Source/Notes" field, enter 1000 in "Distance".
9. Darkvision appears on character sheet, range 1000 feet. Good enough for me.
10. For fun, enter "10,000" in "Distance" field. Sidebar displays "1.893939393939394 miles". lol