Question about append header to binary

Hey guys,

I just had a quick question regarding appending header to a binary file with string data written to it.

As you can see I can read the files correctly if I set  "prepend array or string text size" to TRUE.

but when I set it to false, an error occurs.

I thought each string is assumed to be 1byte, so if I pass the file size in bytes to the read function, it would return me the correct number of strings. Which assumption of mine is incorrect?

Thanks for your help