# What happens if I edit a running scenario?
**Updating a node** - the current users in the node (usually a very small number except wait nodes) finish the scenario with the old version, and all new customers coming to that node (no matter where they're coming from) will flow according to the new version.
**Deleting a node** stops the execution of all unprocessed customers in the node, e.g., customers in the wait nodes will be lost. They won't continue to the next node.
**Creating a new node** or modifying node connection applies immediately, e.g., modifying outgoing connection from a wait node means that existing customers in the node will use the updated connection once they are finished waiting.
# How to investigate error messages in action nodes?
You may encounter an error message in action nodes in the scenario evaluation tab. That applies to action nodes, such as email, browser push, mobile push, webhooks, etc.
As an example, let’s investigate these webhook error messages.
To effectively investigate error messages, follow these steps:
**Create a Detailed Report:** Generate a report that reveals the nature of the encountered error. To begin, decide on the **time frame** for the report. If you're unsure about when the errors started, you can select the **Lifetime option.**
**Set Up Report Rows:** Set `
campaign > messages` in the report rows. This section comprises various messages, including error messages, providing insight into the reasons behind the errors. Ensure that grouping is set to Auto. Choosing None might overwhelm you with excessive error messages. For this discussion, we'll use the Top(4) option to focus on the four key error messages.
**Configure Metrics:** Create a `
count > event > campaign` metric and specify the campaign ID associated with the error-generating messages. Also, indicate the action_id, which corresponds to the node number producing errors. In this example, it's number 9 (you can verify this using the webhook image). If you're interested in all error messages from a particular scenario, you can omit the action_id.
**Choose the Right Metric Settings:** Set the metric to All. Although First could work, it would only represent each error once per customer profile. Opting for All is useful when dealing with numerous errors and needing an overview of their overall distribution.
**Identify Error Sources:** Now, the sources of error messages are visible. You can delve into the root causes of these errors. This webhook in our example has an invalid header name, incorrect authentication, and no access key provided. Remember, these are just sample error messages for this webhook. You can encounter various error messages based on the action node type.
# What happens when a customer fails in a campaign node?
When a customer fails in a campaign node (email, push notification, SMS), the customer does not proceed in the flow of the scenario. The exception to this is webhook which has two outputs: success and fail.