I log into Google Merchant at least once a week to do updates and check for errors and today I logged in to find errors that had never been there before and since I had not make any changes to the code that creates my feed I went to check to see why it was showing the following error:
Apparently Google has changed a lot of the taxonomy of their categories.
Example, what used to be
Vehicles & Parts > Automotive Parts
Vehicles & Parts > Auto Parts
If you need to find what the new categories are here's the link
...] But wait, there's two versions online and they're DIFFERENT
Here's the other one
I highly recommend that you download the version here in excel.