This means your order uses a different currency than the deposit account. This usually happens with Canadian invoices trying to enter a USD Accounts Receivable account. Each account in QB can use a single currency. You must tell Connex to map the account, based on the currency.
How can I tell what currency my account uses?
In QB, go to your chart of accounts. Here is what it looks like:
I received this error with my Accounts Receivable account. How do I map it?
Login to Connex. Hover over the gear and click rules engine. Click add new rule. Add a rule like this one.