QuickBooks script error typically occurs when there is an issue with the scripting or programming code within the QuickBooks software. These errors can manifest as error messages or pop-ups when you're using QuickBooks Online (web-based version) or QuickBooks Desktop (installed version). Script errors can be caused by a variety of factors, including Browser Issues (QuickBooks Online) and corrupted Installation (QuickBooks Desktop). Damaged Company File (QuickBooks Desktop), Conflicts with Third-Party Software.