mod_k2_users corrupts the database and generates this error. A 1 minute video screen grab is attached that shows when and how this happens. Please view it.

ERROR MESSAGE 1054 Unknown column 'juser.usertype' in 'order clause' SQL=SELECT juser.*, k2user.group, k2group.name as groupname FROM psg_users as juser LEFT JOIN psg_k2_users as k2user ON juser.id=k2user.userID LEFT JOIN psg_k2_user_groups as k2group ON k2user.group=k2group.id LEFT JOIN psg_user_usergroup_map as `map` ON juser.id=map.user_id WHERE juser.id>0 GROUP BY juser.id ORDER BY juser.usertype asc LIMIT 0, 100

This error is triggered when accessing the settings for "Retrieve Specific Users" on the back end of this module (K2 v2.6.7, J31, Php 5.3.x). When I sort the UserList by GROUP, this error is triggered and I can no longer access the user database via K2.

video would not upload, but here is an external link.
cloudserver2.com/k2-error.mp4

Hello bertm,

Can you try with K2 v. 2.6.8 DEV build and let me know if the issue persists? getk2.org/assets/get/

After installing K2_v2.6.8-DEV_BUILD I still get the same error, but now the SORT BY COLUMN feature works properly. I can click on each column and the popup window remains in place and allows proper navigation. But when I click on GROUP column header it still fails with the same (or similar) error message.

Try this:

In Joomla Admin area go to Extension Manager > Discover (side bar nav)
Click on the "Discover" button at the top.
Find all of the K2 files that weren't installed and select them. Click on "Install" button at the top.
Go back to Extension Manager > Install
Reinstall the K2 SVN version zip file on top of your old installation.

I have exactly the same issue. As soon as I tried to list the users by Joomla user group I got

Unknown column 'juser.usertype' in 'order clause' SQL=SELECT juser.*, k2user.group, k2group.name as groupname FROM j25_users as juser LEFT JOIN j25_k2_users as k2user ON juser.id=k2user.userID LEFT JOIN j25_k2_user_groups as k2group ON k2user.group=k2group.id LEFT JOIN j25_user_usergroup_map as `map` ON juser.id=map.user_id WHERE juser.id>0 GROUP BY juser.id ORDER BY juser.usertype asc LIMIT 0, 20

I've tried the stuff listed here but none of it worked and I now can't get into the user list in the back end. I'm using Joomla 3.1 and have tried installing the developer release of K2 as suggested.

Hello Mark,

Try to Fix your database. Go to Extensions Manager -> Database -> Fix.