unkown error when writing sql table from R

Question

To print a sql table in SQL Server I wrote the following function:

writeTableSql <- function(table, dat, tablename){
#libraries
 library(RODBC)
 library(ETLUtils)
 library(ff)
 dat[] <- lapply(dat, function(x) if (is.character(x)) as.factor(x) else 
  {x})
 ETLUtils::write.odbc.ffdf(x = ff::as.ffdf.data.frame(dat), tablename = 
   tablename, odbcConnect.args = list(dsn = table, uid = "uid", pwd = 
    "***"))

}

writeTableSql("DDBBname", my_df, "table_name")

While it is working it stops and in the console says :

Browse [1] <

Any guess what could be the issue?