Hi, i have the same problem.
URL:
https://www.pgzeletava.cz/wp-admin/admin.php?page=cvg-gallery-add#linkvideo
Operating System : Linux (64 Bit)
Server : Apache/2.2.3 (CentOS)
MySQL Version : 5.0.95
PHP Version : 5.2.10
PHP Max Upload Size : 100MB
FFMPEG : Not Installed
[Note: Preview images for uploaded videos will not be created automatically using FFMPEG. Manually upload preview images for videos.]
PHP extension SimpleXML
: Enabled
PHP setting allow_url_fopen
: Enabled