Unless box 5 is the same as box 1 then the 1099-R does not indicate a 401(k) to Roth account - it indicates a 401(k) to Traditional IRA account rollover which is tax free.
If box 5 is the same as box 1 then that says that all of the amount consist of your own after-tax contributions (box 5) so none of it is taxable, but in that case box 2a should be blank not zero, but in this case a zero will not mater.
If the 1099-R is improper then you need to contact the plan administrator for a corrected 1099-R.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
