Why error "numerical expression has 50000 elements: only the first used" emerges in R?

Question

I am fitting a null 4 level hlm model with sampling weights on all levels. I get an error that "numerical expression has 50000 elements: only the first used" 6 times and then the model runs. It produces not full output.

The data is in dataframe format with all of the columns being numerical values. There are no missing values.

library(WeMix)

model1 <- mix(result ~ 1 + (1|IDCNTRY:IDSCHOOL:IDCLASS) + 
           (1|IDCNTRY:IDSCHOOL) + (1|IDCNTRY), data=data, 
           weights=c("wgtst", "wgtcl", "wgtsch", "wgtcn"))`

Any help in solving this error would be very much appreciated.