The Library's importer works around server limits on uploaded file sizes by chunking large images into smaller bytes. This should work around any file size limits imposed by your server's PHP configuration, but does require you to be using a relatively recent web browser. If you experience problems or errors uploading large files, you may have to edit your server's file size limit.
View your current limit
Go to Settings > System inside Koken. The table on that page will display the file size limit currently being imposed by the server where Koken is installed.
Raise limit by contacting your web host
The easiest way to resolve this is to contact your web hosting provider and request they raise your file size limit. If they don't respond and you know your way around a server, try the next options.
Raise limit by editing server's php.ini file
Edit the following in your server's php.ini file:
upload_max_filesize = 50M post_max_size = 55M
Note: post_max_size should always be a bit larger than upload_max_filesize, hence the discrepency above.
Raise limit by editing .htaccess
Some web hosting providers allow this to be edited via .htaccess. Try adding the following to
php_value upload_max_filesize 50M php_value post_max_size 55M