Blank page trying to upload in k2

Hello,
When I´m trying to upload a photo with k2, I get a blank page.
I´ve checked all the permission all seems ok, so I don´t know what is the problem.
Thanks in advanced.

I'm also having a similar issue... I'm using the eSport template and trying to add slide images with "Image Show GK4" but when I click on the "Select" button to upload an image, the screen turns gray but nothing happens, the upload box doesn't appear. It's not a browser issue (I've tried it in Chrome, Firefox and IE9) Not sure what to do since this is the only way to upload images for the slideshow, there doesn't seem to be a manual way to do it. (The image upload works in articles, VirtueMart, and all the other places I've tried so far, just not in the slideshow module.)

ibaitxu: If image folders permissions are writable then please check in phpinfo if GD is installed and make sure image filenames are lowercase/nospace between letters.

bamguru: Make sure you are using image show GK4 v1.24 which is currently latest and also while editing any image show GK4 module ( when you are in module settings ) refresh your browser so it can use new style.css file or simply clear your browsers cache/history.

See you around...

Hello again,
The GD is enable and file name it´s only a number, so I don´t know where is the problem.

Go to Components - K2 and click the Information link to see if there are any errors.
* Multibite String must be enabled.
* Check following folder "/media/k2 " and its subfolders for write permission , 755 or 777 for test purpose.
* Check upload limit in php.ini or use a smaller sized images for test purpose.
* Reinstall K2
* Uninstall then reinstall k2.

See you around...

I´ve checked all the points you have commented all seem to be ok.
My only option now is supposed to be the reinstallation of k2.
My question is, will I lose all the settings of k2?
Thanks a lot, I appreciate your effort.

You should backup your website in any case, you can simply use extension manager to install K2. When installing K2 at the end of installation check its installation status to make sure everything is installed.

I found finally a solution, as I read in this post: http://community.getk2.org/forum/topics/k2-information-page-and?id=3536014%3ATopic%3A70384&page=2#comments for me worked this solution:

in the file: administrator/components/com_k2/lib/class.upload.php search :

$this->mime_file = true; // MIME detection with UNIX file() command

and change to

$this->mime_file = false; // MIME detection with UNIX file() command

I see , then that means your server is not configured properly to handle mime types where the server is incorrectly identifying the mime type. So disabling that function works.

Glad you find the solution, see you around...