I think this errors messages are bugs.
Let's take one by one.

"1. Warning: ftp_close() expects parameter 1 to be resource, null given in /.../ftp/index.php on line 131"

I think you receive this message when you push "Logout".
It is trough ?

“2. Warning: ftp_put(): Rename/move failure: No such file or directory in /.../ftp/functions.php on line 69”

This is an bug of my script, when your website is hosted like a subfolder of first domain name. I will repair this bug on future version.
For example, if home directory of first domain name is /var/www/html, if you will put browcoftp into folder /var/www/html/ftp all will work.
But if your web folder is /var/www/html/yoursite and if you will put browcoftp into folder /var/www/html/yoursite/ftp, path to yoursite will not work.
This situation is because I use $_SERVER['DOCUMENT_ROOT'] instruction to determinate witch is current path, and in this situation, DOCUMENT_ROOT is defined by first domain name.

If your site is located in /home/yourname/ and first domain is in /var/www/html, all work well.

In next weeks, i will remediate thats bugs.
Thank you for understand.

Oh, thanks for answering so fast.

It´s not my own server, it´s a webhoster with an virtual server where I have an account. So I can´t change the basic structure. But I will try your bugfixing in future! :)