I have this in multilanguage status:

Warning This site is set as a multilanguage site. The Languagefilter plugin is not enabled although one or more Language Switcher modules OR/AND one or more specific Content language Default Home pages are published.

Notice Warning! A user/author should have only one contact to which is assigned language 'All' OR one contact for each published Content Language

Some of the contacts linked to the user Super User are incorrect.

Details Status:
Language Filter Plugin Disabled
Published Language Switcher Modules 4
Published Default Home pages (including 1 assigned to language "All") 5

Language Published Site Languages Published Content Languages Published Default Home pages

en-GB On On On
es-ES On On On
pt-BR On On On
ko-KR On On On

You should enable the Languagefilter plugin. Otherwise K2 Live seach won't work in mulit-language mode.

Thanks for the help... but finally the point is using K2 with SH404SEF and in Multilanguage... If I active the joomla multilanguage plugin the SH404SEF simply stop working...

Is the new version 2.6.0 fixing this issue?

Regards!