Script errors are in fact errors in Internet Explorer. Even in Windows 10, IE is still present.
And Intuit programs use IE to display many of the screens in QuickBooks.
What it is indicating is an error in Internet Explorer is occurring when it is trying to display portions of the program.
In some cases they are harmless and the script error reporting can be turned off. In other cases there is a problem with IE and there are steps to take:
https://answers.microsoft.com/en-us/ie/forum/all/script-errors/ee9ed848-b73d-49cc-8f92-e25da50c938f
