Call to member function

I have the following code and I'm trying to understand and find a solution for this error.

A PHP Error was encountered

Severity: Notice

Message: Undefi开发者_开发知识库ned property: Tank_auth::$users

Filename: libraries/Tank_auth.php

Line Number: 188

Fatal error: Call to a member function UpdateProfileInfo() on a non-object in /home/xtremer/public_html/kowmanager/application/libraries/Tank_auth.php on line 188

Tank Auth Controller: http://pastebin.com/iRj11hgR Tank Auth Model: http://pastebin.com/qhNK5Whz Tank Auth Library: http://pastebin.com/RVxdzhUa

Edit: Thanks to Marc he was able to find the problem but I do have a new issue oddly.

A PHP Error was encountered

Severity: Notice

Message: Undefined index: userID

Filename: libraries/Tank_auth.php

Line Number: 188
A PHP Error was encountered

Severity: Warning

Message: Cannot modify header information - headers already sent by (output started at /home/xtremer/public_html/system/core/Exceptions.php:170)

Filename: libraries/Session.php

Line Number: 671
A PHP Error was encountered

Severity: Warning

Message: Cannot modify header information - headers already sent by (output started at /home/xtremer/public_html/system/core/Exceptions.php:170)

Filename: helpers/url_helper.php

Line Number: 543

Possibly relevant:

line 187: $this->ci->users
line 188: $this->users->UpdateProfileInfo(...);

forgot a ->ci in Tank Auth Library?

It would appear that your tank_auth/users.php model is not loading, or there is a naming conflict somewhere. What does your $autoload array look like?