rolling regression error message in windows 9

[jason.benderly]

If I use 'fixed window' in roll I get an error message like these:
457 is not a valid index for vector-series-coefficient _RPS03_XX1B01.
405 is not a valid index for vector-series-coefficient _RPS10_X201.

But roll works if I use anchored at start or anchored at end with same equations and variables.
I have not used roll in quite a while and I think I had this same problem before but forgot solution.
Any suggestions?
Thank you.

[jason.benderly]

Found Gareth's fix.
Need to run roll as an add-in, not as an new object.
Thank you Gareth.