Encountering Error in 1:T0 : argument of length 0 with california_prop99

[JoshuaHHess]

Thank you for the package. Up to now, I've been able to use it with ease. Unfortunately, it has recently started to throw an error:

setup = synthdid::panel.matrices(as.data.frame(as_tibble(california_prop99)))
estimate <- synthdid::synthdid_estimate(setup$Y, setup$N0, setup$N1)
Error in 1:T0 : argument of length 0
setup$T0
[1] 19