Overview

On February 2026, Amazon sellers uploading inventory or product feeds may encounter error 90108, which signals that the submitted file does not match the required UIEE (Universal Information Exchange Environment) format. The feed is rejected outright, halting any updates to listings, pricing, or stock until the format issue is corrected—making prompt resolution essential for sellers who rely on bulk uploads.

Key Points

• Error 90108 definition — Indicates the uploaded file fails UIEE format validation, preventing Amazon from processing the feed.
• Complete feed rejection — The system discards the entire submission; no partial rows are saved, so every product in the file remains unchanged.
• Typical cause: wrong file type — Uploading a flat‑file CSV when the feed type expects a UIEE‑structured XML, or vice‑versa, triggers the error.
• Feed type mismatch — Selecting “Inventory Loader” while providing a “Product Feed” template is a frequent trigger.
• Straightforward fix — Align the feed type dropdown with the actual file format, then resubmit the corrected file.

How Error 90108 Occurs

1. Feed type selection — The seller chooses a feed category (e.g., Inventory Loader) in Seller Central or specifies a feed type parameter in the Selling Partner API. If the chosen type expects a UIEE‑encoded XML but the uploaded file is a plain CSV, the validation step flags a mismatch.
2. Initial format validation — Amazon’s ingestion engine reads the file header, checks encoding (UTF‑8 vs. UTF‑16), and verifies required UIEE elements such as <Message>, <OperationType>, and <MessageID>. A missing <Message> tag or an unexpected delimiter causes the engine to reject the file instantly.
3. Error response generation — Upon detecting any structural discrepancy, the system returns error 90108 to the seller’s account or API response, halting further processing before any product data is parsed.