I install new 3.1 joomla on server, main index page work ,after installed K2 v. 2.66 main index page not working , only white screen ...I uninstall K2, index page working , install again K2, index page not working again ..

What I must to do ? :(

THX.

Hello Lucijan,

This can be caused by a lot of things. Is your server running PHP 5.2.x + (ideally 5.3 +) ?
Does your template include K2 overrides which get enabled upon install and cause PHP errors?

In any case your error_log will provide you with some valuable information on what went wrong.
Locate the file (it should at your root folder or a level higher inside a folder called logs) |and look for the fatal errors. If you can't seem to find the error feel free to paste the error here, so we can have a look at it.