You likely can't e-file your state tax return due to a form that TurboTax is waiting for to be finalized. If you know what form it is, you can check the TurboTax Forms Availability Tool for the complete list. If a form shows as "Unsupported" in the "Ready for e-file" column, that particular form would need to be mailed.
TurboTax should notify you but to be safe you can go on your TurboTax program and run all updates to the program until you are able to file. Click here for information on manually updating TurboTax. After the update installs, restart your TurboTax program, select File, and e-file your return.
If you provide your state name, the error message you got and the version of TurboTax you are using, we may be able to help you further.
Click here for Manually Update TurboTax for Windows Software
If you have additional information or questions regarding this, please return to Community and we would be glad to help.