Reading csv file with read_csv

I get the following error reading csv files. Warning: One or more parsing issues, see problems() for details. Please help me fix this. I have no idea how to do this.

you can paste your code here, otherwise its hard to see the problem.

dat <- read_csv("yield_10.csv") # pulled from FRED

Was there anything in dat? A warning isn't necessarily an error.

The problem appears later when I want to use the result of that code. The file has two columns with dates and risk-free returns. I was not able to use the next code because of this first one. here is the whole code.

dat <- read_csv("yield_10.csv")
rff <- dat$Yield

rfree <- (1+rff/100)^(1/12) - 1

you can output dat ,rff, rfree to see which step give you the error

It is the dat, the first one

What is the output of

dat <- read_csv("yield_10.csv")

Do I have to do something to the file before I use it? Should I may be delete one of the columns or something? I only need the second column

Can your post the first few lines of the csv file. Not the data frame that R makes from the csv file but the content of the csv. Open the csv in a plain text editor like NotePad on Windows. Paste the file content here between lines with three back ticks, like this:
CSV data