missing data NA output

[mtsc...@gmail.com]

Dear folks,

I have a dataframe containing numeric and categorical data. One variable contains missing values (original denomination #Null!). After transformation into NA (df[df == "#NULL!"] <- NA) I run descrTable(dataframe) and get the following answer:

Warning messages:

1: In compare.i(X[, i], y = y, selec.i = selec[i], method.i = method[i],  :

  Some levels of 'BMI' are removed since no observation in that/those levels

2: In compareGroups.fit(X = X, y = y, include.label = include.label,  :

  Variables 'BMI' have been removed since some errors occurred

I do not get the  error when using the example dataframe "regicor" also containing missing values denominated as NA and using the same code.

you find the link to my dataframe attached: 

https://drive.google.com/file/d/1aAfEncDr4Y79VTf6CAuLgdR8ImdMZlEk/view?usp=sharing

my used code:

df <- read.csv("acei_error.csv")

library(compareGroups)

df$gender <- factor(df$gender, labels = c("Female patients", "Male patients"))

df$acei <- factor(df$acei, labels = c("no", "yes"))

df[df == "#NULL!"] <- NA

descrTable(df)

many thanks in advance and thank you for your amazing work!