Inventory Location API returns 500 (errorId 25001) / 400 (errorId 2004) on Sandbox - reproduced on two independent test-seller accounts
Summary: tizeic-0 is experiencing issues with the Sell Inventory API's Inventory Location resource in the Sandbox environment for the EBAY_DE marketplace. They report consistent failures with error codes 400 and 500 on two separate test-seller accounts over a five-day period, suggesting a potential platform issue rather than a request-formatting problem. They have ruled out various possible causes like expired tokens and account-specific issues. tizeic-0 is seeking confirmation if this is a known issue or if there is a missing enablement step for using the API.
Hello,
I'm hitting a reproducible issue with the Sell Inventory API's Inventory Location resource in the Sandbox environment (EBAY_DE marketplace) and wanted to check if this is a known platform issue.
App ID (Client ID): TizianEi-Tamo-SBX-5a4cd4de7-efdb8e0c
RuName: Tizian_Eichler-TizianEi-Tamo-S-dzdnpfqiu
Summary: The Inventory Location endpoints fail consistently in Sandbox, on two separate, independently created Sandbox test-seller accounts, over a 5-day span. This looks like an account/platform-side issue rather than a request-formatting problem on my end.
Evidence:
1) Test-seller account #1 (created ~2026-08-04): PUT /sell/inventory/v1/location/{merchantLocationKey} -> HTTP 400, errorId 2004, domain ACCESS, "Invalid request", reproduced with multiple merchantLocationKey values and payload variations. GET /sell/inventory/v1/location (no body) -> HTTP 500, errorId 25001, "System error." Retested ~19 hours later with a freshly refreshed access token: identical results.
2) Test-seller account #2 (freshly created 2026-08-09, specifically to rule out an account-specific cause): new OAuth grant, full sell.account/sell.inventory scopes, confirmed active token. GET /sell/inventory/v1/location with this account's own fresh token -> HTTP 500, errorId 25001, "System error." - identical to account #1.
Ruled out: request body/formatting (reproduced on a bodyless GET), stale/expired token (reproduced right after fresh grants on two different tokens), eventual consistency/timing (reproduced ~19 hours apart), account-specific state (reproduced on a second, brand-new, otherwise unused test-seller account).
Question: is there a known issue with the Inventory Location API in Sandbox for this application/keyset or marketplace right now? Or is there an account/application-side enablement step (similar to the Business-Policy opt-in requirement for the Sell Account API) that isn't documented for Inventory Location?
(For context: I also tried the official Developer Technical Support ticket flow, but the "AI-Assisted Support" submission on developer.ebay.com/my/support/tickets currently seems to misroute to the unrelated "Application Growth Check" form instead of creating a ticket - happy to file it there too once that's working.)
Happy to provide raw request/response logs or timestamps if useful. Thanks!
