That page says I can fix this bug by visiting the image field setting form - where is this located exactly? I can't find it.
Didn't read the linked site, but:
- Image styles are managed here "admin/config/media/image-styles"
- Image Field settings are managed here: Visit "Structure" -> Content types -> Edit %your-content-type% -> Manage fields tab -> Click edit link in the row of %your-img-field%