Ted here from Shopify, thanks for reaching out to us!
Hmmm... this sounds a bit strange. I have a few questions I'd like to ask to help gather more context. Would you be able to tell me the name of the theme you are using? What changes are you hoping to make? Could you show me exactly the steps you are taking for the error to appear? Have you made any changes to the theme previously or have you installed a new app that might have required some coding changes?
Thanks a mill,