V@no,
Here is the details what I did. IF I have uploaded my pictures to my data folder and in ACP I used "Check new images" option and tried to add the images into my gallary, but here I am getting the error messgae. I think my host has some setting to stop php error messages, so I am unable to see the error message.
Another way.
If I am uploading the picture of less size ( within 1600px) then its working fine. If I am uploading the pictures thru website's upload button then the same issue, but not able to check the error message.
I went thru my error log in c-panel and found the following error message.
PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 8868 bytes) in /home/bhwallpa/public_html/includes/image_utils.php on line 80, referer: http://www.bhwallpapers.com/member.php?action=uploadform&cat_id=162