Hi all, 

I found a module in one of the public projects that I wanted to bring into my older otree (1.4.14). However, I run into an issue where Powershell tells me 

module 'otree.models' has no attribute 'StringField'

The whole chunk is

    correct_text = models.StringField(
        doc="user's transcribed text")
        
I would appreciate if someone could point out why this might be happening, as well as if there is a way to fix this.