A transaction sits in your list marked pending, and never moves.
First: this is often completely normal
Not every payment that gets started gets finished.
Customers change their mind at the payment screen. They close the tab. Their bank app times out. Some methods, like a bank transfer, genuinely take days to arrive.
A pending payment is not automatically a problem. It is often just a customer who wandered off.
When it is a problem
If a customer tells you they paid, and the payment is still pending in your admin, then your website never heard the result.
That is the webhook. Go to the article “The payment worked but nothing happened”, because it is the same underlying cause and the same fix.
How the plugin protects you
Even when the webhook fails, the plugin checks in with Mollie every hour and updates anything it missed.
So a payment stuck because of a webhook problem will usually correct itself within the hour.
If it does not correct itself even after that, something is genuinely wrong with the connection to Mollie. Run the Test connection button on the API keys tab.
Checking a single payment
Open the Transactions tab, find the payment, and refresh its status. The plugin asks Mollie directly what happened and updates accordingly.
If Mollie says it was paid, the package activates as it should have done in the first place.