How to fix: Missing attribute value for grouped variants

Some variants in a group have a variant attribute (e.g., color) and others don't; all must be consistent.

Each product attribute in Google's spec has format and value rules. Issues here are usually: missing required attributes for the category, invalid enum values (e.g., 'XL' submitted where 'M, L, XL' is the valid set), out-of-range numbers, or attributes that conflict across the feed.

1. Look up the affected attribute in Google's product data specification: https://support.google.com/merchants/answer/7052112.
2. Check whether the attribute is REQUIRED (must be set) vs RECOMMENDED (optional but helpful) for your product category.
3. For enum-style attributes (gender, age_group, condition), use ONLY the documented values exactly.
4. For free-text attributes, stay within the character limit and avoid promotional language.
5. Re-upload the feed and check the next processing cycle.

• Submitting 'unisex' for `gender` when the spec only accepts 'male', 'female', or 'unisex' — case matters
• Using 'Adult' instead of 'adult' for age_group — Google's enum check is case-sensitive