I happen to see this uu_upload.pl download prompt error when installing phpmotion on a subfolder. This is because Apache doesn’t understand this perl file in cgi-bin.
Here is a fix which worked for me
Create a .htaccess file in cgi-bin of the subfolder and add the entry
Options +ExecCGI AddHandler cgi-script .pl
This error can also happen if you haven’t given the correct path for cgi-bin in uploader_conlib.php file
$path_to_upload_script = '/myvideos/cgi-bin/uu_upload.pl'; $path_to_ini_status_script = '/myvideos/cgi-bin/uu_ini_status.pl';
myvideos replace it with subfolder name.