button and select Error Console to display it. Sometimes things may not go as you planned and you might face an error message in Nuke. When this happens, an error alert displays in the Viewer and on the node that has a problem in the Node Graph. The error message itself prints in the Error Console tab next to the Properties Bin. If you have an error in a Read or a Write node, or you are missing a plug-in, the error message also displays in a pop-up window.
If you see an error alert on your node or in the Viewer, you can click the Error Console tab to open it and view the error message. If you can’t see the Error Console, click the content menu button and select Error Console to display it.
In the Error Console error list, you can double-click on a message and, if possible, Nuke takes you to the control panel of the node that’s in error. This isn’t always possible because of the nature of the error. You can also click the clear output 
button on the Error Console to clear all error messages on the tab.
NOTE: If you have a node in your Node Graph that is producing an error, but it’s not connected to the node tree, Nuke won’t show a pop-up error message for the node and you can still view the resulting image in the Viewer, if you have one connected. This enables working without having to stop to close error messages in the event that you have erroring nodes in the script that aren’t connected to your node tree.