Yes to both questions.
I have installed, set up and worked with WordPress(es) network before on this and other hosts. Recently thought my database was erased (server issues) and may back ups were corrupt so I re-created the whole site from the ground up – followed the instructions and now when I enable that piece of code (and this issue is so new to me I have never had it before) I get logged out like it sais (or I log out) I enter in My user name, my password and then all that happens is the page refreshes with the user name filled in and the password left blank.
No error messages, no issues (in terms of database, password, username, server connection)
I disable that piece of code and I can log in.