Read.csv: some rows are missing

read.csv in R doesn't import all rows from csv file

The OP indicates that the problem is caused by quotes in the CSV-file.

When the records in the CSV-file are not quoted, but only a few records contain quotes. The file can be opened using the quote="" option in read.csv. This disables quotes.

data <- read.csv(filename, quote="")

Another solution is to remove all quotes from the file, but this will also result in modified data (your strings don't contain any quotes anymore) and will give problems of your fields contain comma's.

lines <- readLines(filename)
lines <- gsub('"', '', lines, fixed=TRUE)
data <- read.csv(textConnection(lines))

A slightly more safe solution, which will only delete quotes when not just before or after a comma:

lines <- readLines(filename)
lines <- gsub('([^,])"([^,])', '\\1""\\2', lines)
data <- read.csv(textConnection(lines))

REF:
https://stackoverflow.com/questions/26094584/read-csv-in-r-doesnt-import-all-rows-from-csv-file