Can't read password from config using --defaults-extra-file in MySQL
It looks like the access issue due to permissions level.
Try running the batch file as administrator by right clicking on it and then selecting Run as administrator ,Try wrapping your password with in '' if it contains special characters,Try removing any extra space that might be getting added,also please find few more solutions to similar problem here :

As per examples from http://dev.mysql.com/doc/refman/5.7/en/option-files.html
The password should look like:

[client]
# The following password will be sent to all standard MySQL clients
password="my password"