Question / Problem:
If you edit Minimum/Maximum length of an input in a Template then go back and edit the template and delete the values, the Max/Min length fields look like there is no set value:
But it seems they are set to 0.
Because if you try to run the Kapplet that is based on the template you cannot enter any characters. The Run button is enabled only when you do not have anything typed as soon as you type something the button is disabled. This fits the scenario of both min and max length being 0.
Answer / Solution:
This is a Bug: Bug 1477172:Kapplets v11: If you enter custom values for Minimum/Maximum length then remove them, it seems their values are set to 0
It was reported in 18.104.22.168.
Set a high number for Maximum length in Template and update Kapplet from template