Common Nitromule errors and fixes

Updated 2026-09-07

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Use this catalog to match an error message or symptom to a fix. Start with the section that matches what you were doing — rates, labels, stores, or payment.

Rates and addresses

Symptom / message	Likely cause	Fix
No rates / empty rate shop	Incomplete address, weight, or dims	Fill ship-from/to, weight, L×W×H; see rates not showing
Only USPS rates	PO Box or USPS-only destination	Confirm address type; use a street address for UPS/FedEx
Address invalid / undeliverable	Missing unit or bad ZIP	Validate address; add Apt/Suite
Rates much higher than expected	DIM weight, residential, extras	Remeasure; check signature/insurance; compare service levels
BYOA rates missing	Carrier account disconnected	Reconnect under your own accounts

Label purchase and printing

Symptom / message	Likely cause	Fix
Payment required / 402	No Billing card for platform rates	Add payment method; retry purchase
Purchase failed after pay	Carrier or network error	Retry once; check status page if widespread
PDF will not print correctly	Fit-to-page / wrong paper	100% scale; printing labels
Need label again	Looking for repurchase	Download Label — do not Place Order twice
Void failed	Already scanned / too late	Contact carrier; see refund a label

Stores (WooCommerce & eBay)

Symptom / message	Likely cause	Fix
Woo authentication failed	Bad or partial keys	Regenerate credentials; paste all four fields; Woo troubleshoot
Woo could not reach store	Permalinks Plain / firewall	Non-plain permalinks; allowlist `/wp-json/`
eBay OAuth did not connect	Pop-up blocked	Allow pop-ups; reconnect; eBay sync
Orders missing	Status not exported / not awaiting shipment	Adjust Woo export statuses; confirm eBay paid state; Sync
Tracking not on channel	Labeled via Get Label	Create Label from the imported order

Portals

Symptom	Likely cause	Fix
Portal shows no rates	Restrictive rules or empty presets	Add presets; loosen rules
Wrong logo / domain	Branding not saved on that flow	Branding and subdomain
Customer paid, no label	Checkout/provider glitch	Find portal order id; retry download; contact support

Account and access

Symptom	Likely cause	Fix
Cannot connect stores	Plan without store connections	Plans overview — Business for stores
API key rejected	Wrong key env or revoked key	Use `nm_test_` vs `nm_live_` correctly; rotate in Settings → API
Login issues	Password / session	Login and password

Still stuck?

Note the exact error text, time (UTC), order id, and store name.
Retry once after fixing the matching row above.
Check whether only one carrier fails (carrier-side) vs all carriers (your shipment data).
Contact Nitromule support with those details.

Deep dives: WooCommerce connection, eBay sync, address validation.