Same problem here. The K2 Upgrade kept failing so I manually downloaded 2.6 and installed it. Now I'm getting this same error message.

I have the same problem. Unfortunately before understanding that was a k2 problem I have update two of my domains!
:(
No solutions I see
:(

hi
i have the same problem here,after i upgraded from v2.5.7 to v2.6 from joomla panel i got the same error :

Model class cpanelModelCpanel not found in file
even worse is that Mini K2 module gives error too:
Please check your setting to get the items or maybe you need to write your K2 items first
does installing v2.5.7 solve the problem?
unfortunately i don't have the v2.5.7,where can i download it?
and i wonder to know if installing previous version delete the existing data in database?!
oooooh god why did i do the upgrade!!! :(
i hope someone finds a solution!

Workaround reinstall the previous version, I leave a link to download it, I'll leave a few days until they fix the new version (remember to backup your database):

www.box.com/s/fgbjd2maqm6468k7nv3g

File no longer available for download

thanks dude!

Does any of the admin (or developer of the extension) aware of this error?

Anyone having the " Model class cpanelModelCpanel not found in file " error under K2 2.6 just remove the file /administrator/components/com_k2/models/cpanel.php.

@Михаил Новак

What version of Joomla! are you using? K2 2.6 only supports Joomla! 1.5, 2.5 and 3.0.

Hi Everyone,

Anyone having the " Model class cpanelModelCpanel not found in file " error under K2 2.6 just remove the file /administrator/components/com_k2/models/cpanel.php.

I followed this instruction and the problem was solved, however, I have one question, might this not affect any of default K2 features?

Yes, it does work since I remove the file. But I have the same concern with Tomy Francois, does this effect the whole K2 system? If doesn't effect, why does it exist? Can the developer totally remove from the K2 package so that no one will see that error message again?

Tomy Francois wrote: Hi Everyone,

Anyone having the " Model class cpanelModelCpanel not found in file " error under K2 2.6 just remove the file /administrator/components/com_k2/models/cpanel.php.

I followed this instruction and the problem was solved, however, I have one question, might this not affect any of default K2 features?

Regard the Mini K2 module from Template Plazza, there on their website is a new version updated v.1.2 (Oct 2012 v.1.2 fixed helper.php to be compatible with K2 v.2.6.0) for K2 v2.6.0. Just download, install on top on the old one already installed and empty the cache if is enabled. It should work without any problem. Worked in my case.

@Tomy Francois + Joseph

This file is not used anymore. In the next release we are going to add an automatic removal of the file in the installation proccess.

If anyone still has this problem and is really annoyed by the error message there is a simple fix.
The problem occurs because of the line 360

K2Model::addIncludePath(JPATH_ADMINISTRATOR.DS.'components'.DS.'com_k2'.DS.'models');

in file plugins/system/k2/k2.php

you can replace it with the following,

require_once (JPATH_ADMINISTRATOR.DS.'components'.DS.'com_k2'.DS.'models'.DS.'item.php');
require_once (JPATH_ADMINISTRATOR.DS.'components'.DS.'com_k2'.DS.'models'.DS.'categories.php');
require_once (JPATH_ADMINISTRATOR.DS.'components'.DS.'com_k2'.DS.'models'.DS.'category.php');
require_once (JPATH_ADMINISTRATOR.DS.'components'.DS.'com_k2'.DS.'models'.DS.'comments.php');
require_once (JPATH_ADMINISTRATOR.DS.'components'.DS.'com_k2'.DS.'models'.DS.'cpanel.php');
require_once (JPATH_ADMINISTRATOR.DS.'components'.DS.'com_k2'.DS.'models'.DS.'extrafield.php');
require_once (JPATH_ADMINISTRATOR.DS.'components'.DS.'com_k2'.DS.'models'.DS.'extrafields.php');
require_once (JPATH_ADMINISTRATOR.DS.'components'.DS.'com_k2'.DS.'models'.DS.'items.php');
require_once (JPATH_ADMINISTRATOR.DS.'components'.DS.'com_k2'.DS.'models'.DS.'model.php');
require_once (JPATH_ADMINISTRATOR.DS.'components'.DS.'com_k2'.DS.'models'.DS.'settings.php');
require_once (JPATH_ADMINISTRATOR.DS.'components'.DS.'com_k2'.DS.'models'.DS.'tag.php');
require_once (JPATH_ADMINISTRATOR.DS.'components'.DS.'com_k2'.DS.'models'.DS.'tags.php');
require_once (JPATH_ADMINISTRATOR.DS.'components'.DS.'com_k2'.DS.'models'.DS.'user.php');
require_once (JPATH_ADMINISTRATOR.DS.'components'.DS.'com_k2'.DS.'models'.DS.'usergroup.php');
require_once (JPATH_ADMINISTRATOR.DS.'components'.DS.'com_k2'.DS.'models'.DS.'usergroups.php');
require_once (JPATH_ADMINISTRATOR.DS.'components'.DS.'com_k2'.DS.'models'.DS.'users.php');


basically instead of using the method addIncludePath to include the files in the model folder you call require_once for each file in the modle folder.

@chris

Using the API is the prefered method to load models. It's also much more shorter. I also think that is more easy for a non programmer to just remove a file than messing with code. Anyway we have already fixed that in the SVN version.

Hi Lefteris,

Sorry for the late reply.

Fatal error: Call to a member function categoriesTree() on a non-object in /home/.../public_html/sites/test/administrator/components/com_k2/views/items/view.html.php on line 124

Joomla 2.5.7
K2mart
K2 - Css4K2
PHP 5.3.17

After the update, the error occurs when the administration should be selected K2 articles.
Delete the file / administrator/components/com_k2/models/cpanel.php.
but the error persists. If you want to give access to the site.
Regards !!!

I did remove that file and the error message disappeared, but now it is not possible to order k2 items. The little blue arrows appear in grey and do not work.

¿Is that a bug or it has been removed on purpose?

Reinstalling version 2.5.7 everything works fine




Regards

Jose

Exactly same problem as Jose ^

Now I can't change item's order.

Hello removing your suggested file administrator/components/com_k2/models/cpanel.php. gets rid of the error message, but certain problems are continuing, such as using my Captify Content module - the assigned position for the module gives me the following error message instead of showing my images:

K2 is not installed! Error! Unable to retrieve any Images!

As far as I can see K2 appears to have installed, as I am able to add K2 content generally, so why am I getting the above error message?

Thanks in advance for your help.

@Jose @Eduardo Santos

The ordering function has not be changed. You just need to first sort by the Order column.

@jacob

You need to contact the developers of the module. Probably the will already have an update.

@Михаил Новак

When does the error occur? Are you using K2 2.6.1?