On Cass route [pronoun] used in the script lines causes a trackback error. Had to open the script file and change [pronoun] to her. Later on there was an error with one of Han's images where it didn't appear and just showed a h surprise grey image instead.
In the Cass script there are many spots that have [pronoun] but when I hit the first 2 in the script they threw up some type of key error. After that is when I opened the script and replaced them with her. The first spot I hit the error was the get the Velsings to chase you option.
a "You won't be able to tell the others anything once I catch [pronoun]!"
h "Sigh… not if I'm the one who catches [pronoun]."
*Edit*
I played it again and I think I know what happened the game glitched or something at the beginning as I don't remember having a select pronoun option the first time I played it but the option was there this time and I never hit that error there after picking her for the pronoun.