After upgrade K2 to 2.7.1 search not works!
Enter a search phrase, the page is reloaded but nothing is. More precisely, the page does not change.

I got this issue too. After upgrade to 2.7.1. K2 search in Backend (don't have a Frontend search) does not work for Greek words.
It will work for "test" but not for "τεστ".

yes! don't work with RU words!

Replace 39 and 149-line atin file "site\administrator\components\com_k2\models\items.php"

yes. this is work. but search key words don't save in search field after press button search!

Replace 36-line atin file "site\administrator\components\com_k2\views\items\view.html.php"

and move 41-lineafter 24-line
result

thanks Vladislav. it's work! good day!

Fixed search in other sections:

Categories

Replace 31 and 153-line atin file "site\administrator\components\com_k2\models\categories.php"

Replace 36-line atin file "site\administrator\components\com_k2\views\categories\view.html.php"

insert codeafter 24-line
result
Tags

Replace 34 and 79-line atin file "site\administrator\components\com_k2\models\tags.php"

Replace 32-line atin file "site\administrator\components\com_k2\views\tags\view.html.php"

insert codeafter 23-line
result
Comments

Replace 34 and 78-line atin file "site\administrator\components\com_k2\models\comments.php"

Replace 34-line atin file "site\administrator\components\com_k2\views\comments\view.html.php"

insert codeafter 24-line
result
Users

Replace 36 and 142-line atin file "site\administrator\components\com_k2\models\users.php"

Replace 36-line atin file "site\administrator\components\com_k2\views\users\view.html.php"

Extra Fields

Replace 34 and 92-line atin file "site\administrator\components\com_k2\models\extrafields.php"

Replace 33-line atin file "site\administrator\components\com_k2\views\extrafields\view.html.php"

insert codeafter 24-line
result

url for download?