This dialog box is occurring because LabVIEW's Automatic Error Handling is turned On. The error dialog can be disabled in new VIs by opening a blank VI and navigating to Tools>>Options>>Block Diagram, scrolling to Error Handling, and deselecting Enable automatic error handling in new VIs. This will disable automatic error handling in the block diagram for all newly created VIs in LabVIEW.
You can also disable automatic error handling in a single VI by navigating to File >> VI Properties >> Execution, or clicking Ctrl+I.
Note: The best practice would be to ensure you incorporate manual error handling. If you truly do not care about the output of a specific VI, you can use the Clear Errors VI to clear the error and not have Automatic Error Handling catch and display the dialog box.