Order Accept Encountered Problems Invalid Tenure
This error message means that you are trying to add an order for a billingcycle which has not been setup in your reseller account.
You have setup in WHMCS a hosting product with a billing cycle "Quarterly" (3 Months). You need to add/activate the 3 months price slab in your reseller account for the product you sell through WHMCS. The Pricing in your reseller account does not matter. You need to setup all pricing in WHMCS.