There are a couple things to comment:
1) your file format appears to be an INI file. You should maybe use the Config File VIs to read keys from the file instead of reading the entire file as text.
2) Your Example VI is using low-level File IO functions, and improperly. If you are trying to read the entire file, then you need to find the EOF to know the file size and then read that many bytes.
I have attached an example with a few options for you to look at.