Five checks prevent most import problems.
A reference is an existing CMS item, not free text.
The mapping dropdown shows the field type and the collection connected to it:
categories — MultiReference → Activities
This means every imported category must already exist inside the Activities collection.
If the CMS item is named Restaurant, enter Restaurant. A typo such as Restourante is a different value and cannot be connected safely.
Copy the Name directly from the referenced Webflow collection when you are unsure.
Open an error to see what happened and what to do next.
What it means: The value does not match an existing item in the collection connected to that Reference field.
What to do: Check the collection shown in Map Fields and copy the referenced item's Name exactly from Webflow CMS. Correct spelling, spaces, and punctuation, then validate again.
What it means: Webflow already has an item or localized variant using that slug. It may be a draft, archived item, another locale, or an item created during an earlier partial sync.
What to do: Refresh CMS Smart Sync and inspect every locale, draft, and archived item. If this should be a new item, use a unique slug. Do not repeatedly press Sync with the same slug.
What it means: A required Webflow field is empty or mapped incorrectly.
What to do: Return to Map Fields, find every field marked Required, and provide a value for every row.
What it means: Update mode could not safely identify an existing item. Smart Sync will not guess and update the wrong record.
What to do: Include the exact existing Name or slug, select the correct locale, refresh the collection, and validate again.
What it means: The secure connection between the Designer Extension and Webflow Cloud expired or was interrupted.
What to do: Close CMS Smart Sync, reopen it from Webflow Designer, and retry. Your unsynced review table may be recovered automatically.
Do not immediately repeat the same request.
It identifies the field or value that stopped the operation.
Webflow may have accepted some items before rejecting a later one. Refresh to see what already exists.
Correct the reference, required value, slug, or mapping named in the error.
Confirm that existing rows now show Update instead of Create when appropriate.
AI prepares the table; you approve what reaches Webflow.
Two quick rules for larger workflows.
Select the intended CMS items and image fields before uploading. Review automatic matches, especially when filenames are similar.
Confirm the viewing, update, and create locales separately. After any failure, inspect every selected locale before retrying.
Still stuck?
Include the collection name, locale, Create or Update mode, the exact error message, and a screenshot of Map Fields or Review Data. Never send API keys or access tokens.