ERR_CURRENCY_CONV on Xero: Currency conversion error. Root cause: The foreign currency conversion failed because the required exchange rate is missing, outdated, or outside the acceptable variance range configured in the accounting system. Multi-currency transactions require a current exchange rate to convert the transaction amount to the base currency, and stale or missing rates will block the transaction from posting. Step 1: Check exchange rate. Verify rate is set Step 2: Update rate. Set current exchange rate Step 3: Check conversion. Verify formula correct Step 4: Recalculate. Force conversion recalculation