basically, the short of it is when adjusting the radius of the cities in the custom options of lost cities, I accidently pressed my key input too fast, and rather then Backspacing the initial number of 200 on the maximum radius to replace it with 100, Minecraft froze up during its generating of a preview screen-- to be more exact, it froze because it thought I was trying to generate cities with a maximum radius of 2100 because apparently I didn't press the backspace key hard enough to remove the 2 before pressing 1.

If this is a known issue then I'm sorry for wasting your time.
I didn't see anything listed by name that would have made it obvious that this sort of crash has already been mentioned before and figured it might be worth mentioning since it literally froze up Minecraft to the point where I just had to force close it via task manager End tasking it after waiting it out for 5 mins for Minecraft to unfreeze.

This is only my suggestion but I would like to suggest a feature that forces a Cap value on the Min and Max radius, preventing users from typing a number past the said cap value in the radius sections; similarly to how any attempts to enter a value over 1 entered for rarity & threshold values automatically get turned into 1.0 (which is their cap values).

I forgot to mention originally that this issue occurred in the recent 1.16.5 version of the mod. (LostCities - 1.16-4.0.9-beta)