Hello, I am a joomla newbie and I am working on my first joomla page.
I have a problem with creating a new user groups in K2 extension, when I try to create a new group it shows me an error 1054:

Unknown column 'permissions' in 'field list' SQL=INSERT INTO `zgrxp_k2_user_groups` (`id`,`name`,`permissions`,`access`) VALUES ('','dsf','{\"comment\":\"1\",\"frontEdit\":\"0\",\"add\":\"1\",\"editOwn\":\"0\",\"editAll\":\"1\",\"publish\":\"0\",\"editPublished\":\"0\",\"inheritance\":\"0\",\"categories\":\"all\"}','1')

Strange thing is that it works on localhost, but not on the server. Also on localhost I dont have any default user group, but on the server there are several "default" groups like "Event list 1" , "Event list 2", "Stuff & Administration" which I didn't create. I can delete those "default" groups but I can not edit them.

Are you using K2's latest version on the production server?
Are you using any 3rd party K2 or ACL extensions?

I am using the latest version of K2 and I am not using any third party K2 or ACL extension.
I might know where the problem is but I don't know how to fix it.
When I tried to install the K2 extension, there was an error 1146 which didn't allowed me to upload it (www.joomlaworks.net/forum/k2-en/39917-can-t-upload-k2-v2-6-9-on-joomla-3-3-6). I fixed the problem with the solution from another forum (joomla.stackexchange.com/questions/7164/error-1146-while-installing-k2-extension) and it seems to work, but now it doesn't allow me to create new user groups.
Any idea how to fix it?

Try reinstalling K2.