Thanks for reaching out. I'm here to help.
Another user (@Arboleda) mentioned they were experiencing a similar error. If your product is a custom product, then this is likely a display error and there is nothing you would need to do to move forward. The Google product categories should be working fine.
I also added some questions to troubleshoot in my reply on this thread earlier here. Can I get you to answer those questions? I would be happy to take a look after you've provided me with more details on what you've tried and to these questions.
I look forward to hearing from you,
@Tira Thanks.. Already got the response from Shopify support team that they are aware about this error and technical team are in touch with google to find solution. And as per them this error won't affect the shopping ads but only affect on free listing.