login-image results in many erorrmessages

I just installed login-image within a multisite-WP-installation (network-admin level) and tried to upload an image (jpg).
What happens is: many lines of errormessages occur that I don't understand.
Can anyone help please?

Warning: move_uploaded_file(/www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-content/login-image/login-image copy.jpg) [function.move-uploaded-file]: failed to open stream: No such file or directory in /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-content/plugins/login-image/login-image.php on line 152

Warning: move_uploaded_file() [function.move-uploaded-file]: Unable to move '/tmp/phpEnxxmO' to '/www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-content/login-image/login-image copy.jpg' in /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-content/plugins/login-image/login-image.php on line 152

Warning: Cannot modify header information - headers already sent by (output started at /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-content/plugins/login-image/login-image.php:152) in /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-includes/pluggable.php on line 876

Warning: file_get_contents(/www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-content/login-image/login-image copy.jpg) [function.file-get-contents]: failed to open stream: No such file or directory in /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-content/plugins/login-image/login-image.php on line 162

Warning: imagecreatefromstring() [function.imagecreatefromstring]: Empty string or invalid image in /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-content/plugins/login-image/login-image.php on line 162

Warning: Cannot modify header information - headers already sent by (output started at /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-content/plugins/login-image/login-image.php:152) in /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-includes/pluggable.php on line 876

Warning: Cannot modify header information - headers already sent by (output started at /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-content/plugins/login-image/login-image.php:152) in /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-includes/pluggable.php on line 876

Warning: imagecreatetruecolor() [function.imagecreatetruecolor]: Invalid image dimensions in /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-includes/media.php on line 937

Warning: imagecopyresampled(): supplied argument is not a valid Image resource in /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-content/plugins/login-image/login-image.php on line 180

Warning: imagedestroy(): supplied argument is not a valid Image resource in /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-content/plugins/login-image/login-image.php on line 187

Warning: imagepng(): supplied argument is not a valid Image resource in /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-content/plugins/login-image/login-image.php on line 189

Warning: Cannot modify header information - headers already sent by (output started at /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-content/plugins/login-image/login-image.php:152) in /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-includes/pluggable.php on line 876

Warning: imagedestroy(): supplied argument is not a valid Image resource in /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-content/plugins/login-image/login-image.php on line 192

Warning: stat() [function.stat]: stat failed for /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-content/login-image/ in /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-content/plugins/login-image/login-image.php on line 194

Warning: Cannot modify header information - headers already sent by (output started at /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-content/plugins/login-image/login-image.php:152) in /www/htdocs/w009b486/Domains/zentrumdesneuenseins/wp-includes/pluggable.php on line 876