[R] plm empty model error

[Sojin Kim]

Hi,

I am trying to estimate a two-way model with both individual and time fixed
effects. I am using plm with "twoways" specification.

plm(as.integer(yvar) ~ xvar, index = c("id", "time"), model="within",
data=dataset, effect = "twoways")

But I get keep getting the following message and I don't know what to do
about it, because I don't think anything is wrong with my indices (but
please correct me if I'm wrong on this!). : Error in plm.fit(formula, data,
model, effect, random.method, random.models,  :
  empty model

The data is attached in the email.

Thank you so much in advance for your help.