Mismatch between file and format character vector but the CSV file contains only numerics?

I am receiving this error when trying to read a csv file that appears to contain only numeric values:

Could there be something wrong with the format of the values in the csv file? Each value ends in a newline, except for the last one.

Answer 1

[per isakson]

dlmread() fails to read and convert quoted digits, e.g. "123","456","789". Neither does csvread(). See Comma-separated values. On R2018b

>> dlmread('cssm.txt')
Error using dlmread (line 147)
Mismatch between file and format character vector.
Trouble reading 'Numeric' field from file (row number 1, field number 1) ==> "123","456","789"\n 
>> csvread('cssm.txt')
Error using dlmread (line 147)
Mismatch between file and format character vector.
Trouble reading 'Numeric' field from file (row number 1, field number 1) ==> "123","456","789"\n
Error in csvread (line 48)
    m=dlmread(filename, ',', r, c);     

Proposal:

Use the interactive tool Import Data to read the data directly or create a customized function.

[Walter Roberson]

There is the inherent problem that double-quoted numbers are to be considered character strings in csv files, not numeric.