I try to add item image but when i click on save button show blank page and item saved but image don't save

any Solution ?

If you are receiving a blank page, turn joomla error reporting to maximum and look for an error instead of a blank page...
Check the information tab on the k2 dashboard, look for mb_string encoding - is it enabled on your server?

"If you are receiving a blank page, turn joomla error reporting to maximum and look for an error instead of a blank page... "

i do this no error showing

Check the information tab on the k2 dashboard, look for mb_string encoding - is it enabled on your server?
Multibyte string support=Enabled

also Attachments tab dont working show blank page when i try to attach a file

@mohsen

If you are using AllVideos or Simple Image Gallery plugins remember to enable their debugging setting also.

Lefteris Kavadas wrote: @mohsen

If you are using AllVideos or Simple Image Gallery plugins remember to enable their debugging setting also.

i dont using AllVideos or Simple Image Gallery plugins

You should find out why your system does not print the errors even if it is setup to do so. Without a specific error we cannot help you further. We can just guess. So try to go to K2 information and see that everything is fine there. Also try to increase your PHP's memory limit.

I do have the same error.
My debugging shows:

Call stack
# Function Location
1 JAdministrator->dispatch() JROOT/administrator/index.php:46
2 JError::raiseError() JROOT/administrator/includes/application.php:164
3 JError::raise() JROOT/libraries/joomla/error/error.php:251

any idea?

Regards,
Volkmar

This is not the actual error. Probably some other extensions are suspendig the error. You need to find them and disable in order to see the actual error. Try to disable some system plugins first.

I was dancing about exactly same problem last 4 days. Now it looks I finally solved it.
In my case was problem the php extension "Suhosin".
So I disable it by custom php.ini in administrator folder. But after that disappeared main administrator menu. So I find, there is some bug in php or apache, when you are using custom php.ini, and this bug disable PDO extension as well. So I have to enable PDO again in my php.ini.

My php.ini in admin folder is like this:

extension=pdo.so
extension=pdo_sqlite.so
extension=sqlite.so
extension=pdo_mysql.so
suhosin.simulation = On


Check if is on your server used bloody "Suhosin".