Exporting C# - Webdriver path is not clickable

After choosing “Export” for a test case in Katalon recorder and then choosing “C# (Nunit Webdriver” the webdriver path textbox is not clickable and does not seem to be responding to anything.

I chose other frameworks to compare, and it works with some other choices of framework(but not all).

Am I doing something wrong? the export button in the lower right corner is of course greyed out too.

@ThanhTo @nam.nguyen