This error means that the signature that has been entered under Stripe → Basic Settings → Webhook Signature is incorrect. When entering a webhook signature, it is important to use the signature for:

1. The correct mode of the module (i.e. Live Mode or Test Mode), and

2. The correct signature for the specific webhook endpoint. If you needed to delete and recreate the webhook endpoint before, then you would also need to update the signature as that may have been changed.

Please note that the webhook signature is optional. Removing it completely is also likely to resolve the problem.