"Checkout doesn't work" is really two different problems with two different fixes. Start by identifying which one you have:
WeeConnectPay isn't offered at checkout at all: customers don't see it as a payment option.
The payment is attempted but fails: the customer enters card details and gets a decline or an error.
Case 1. WeeConnectPay is missing at checkout
When the connection between your store and your Clover account is broken, WeeConnectPay hides itself from checkout on purpose: rather than letting customers attempt payments that cannot be processed, the payment option disappears until the connection is restored.
Confirm it by logging in to your WordPress admin. A disconnected store shows a red notice such as "WeeConnectPay can no longer reach your Clover account, so payments are not being processed. Please go to WeeConnectPay settings and sign in with Clover again to reconnect." with a Go to WeeConnectPay settings link.
The fix is exactly what the notice says: go to WooCommerce → Settings → Payments → WeeConnectPay and sign in with Clover again. Once reconnected, the payment option reappears at checkout on its own. The full walkthrough, including why this happens, is in Reconnecting WeeConnectPay and Clover.
If there is no red notice and WeeConnectPay is still missing at checkout, check that the gateway is enabled under WooCommerce → Settings → Payments (the toggle next to WeeConnectPay in the payment methods list).
Case 2. The payment is attempted but fails
First, distinguish a decline from an error:
A decline means the payment reached the card networks and was refused: insufficient funds, incorrect card details, or the issuing bank saying no. Declines are between the customer and their bank; there is nothing to fix on your store. If every card is being declined, including cards you know are good, treat it as an error instead and keep reading.
An error means the payment didn't complete for a technical reason. The order notes on the WooCommerce order usually carry the specific message, so check them first: WooCommerce → Orders → the order → Order notes.
The most common error cause: currency
Your Clover account processes payments in its own currency (for most of our merchants, CAD). If your WooCommerce store is set to a currency your Clover account can't accept, payments fail at payment time even though checkout looks normal up to that point.
Check WooCommerce → Settings → General → Currency and compare it with your Clover account's currency (visible on your WeeConnectPay dashboard). If they don't match, either set your store currency to match your Clover account, or talk to Clover about what currencies your merchant account can accept.
Still failing? Send us a debug log
If the order notes don't make the cause obvious, the fastest path to a fix is a debug log: it records exactly what your store and our servers exchanged with Clover for the failing payment. The article Enable Debug Mode and send us a debug log walks you through it step by step.
Email the log to support@weeconnectpay.com along with the order number, the time of the attempt, and what the customer saw on screen. With those in hand, most checkout failures are diagnosed in the first reply.