PLEASE NOTE: eBay errors are common. If your item is receiving an eBay Error when trying to list, you can learn more by clicking "Read error message" to see what eBay is asking from your listing.
This eBay error relates directly to the "Item Specifics" and "All Variant Specifics" section of the pop up listing modal for the item you are trying to list.
Item Specifics need to be uniform across all the variants you wish to list. If there is a dimension for one variant in the "Item Specifics" section that same Dimension, along with the corresponding value, needs to be applied to all of the variants. This error means you have a Dimension and Value for one variant but are missing that Dimension and corresponding value for one or more of the other variants.
The only Dimensions and Values that should be in the "Item Specifics" for an item are the specifics that make the variants differ from each other. Otherwise, the listing will fail.
For specifics that apply to ALL of the variants, use the "All Variant Specifics" section which can be found only under the Parent ASIN within the pop up listing modal.