TurboTax 2016 For Windows Error 21080488280
In some cases users may experience the following error codes when launching TurboTax and installing updates:
21080488280, 18424896937, or 18424896937.
we have identified these errors as being related to an issue where a TurboTax update has only partially installed.
Manually updating TurboTax will resolve this issue. You can download the manual update here.