그누보드사용중 갤러리와 썸네일부분에서 문제가 생긴것같아요 도와주세요!

Fatal error: Uncaught Error: Call to undefined function imagecreatefromjpeg() in /home/grayson/html/lib/thumbnail.lib.php:244 Stack trace: #0 /home/grayson/html/lib/thumbnail.lib.php(58): thumbnail('1982649603_ibKF...', '/home/grayson/h...', '/home/grayson/h...', 528, NULL, 352, true, 'center', false, '80/0.5/3') #1 /home/grayson/html/theme/basic/skin/latest/gallery/latest.skin.php(11): get_list_thumbnail('blog_sns', '27', 528, 352) #2 /home/grayson/html/lib/latest.lib.php(83): include('/home/grayson/h...') #3 /home/grayson/html/theme/basic/index.php(13): latest('gallery', 'blog_sns', 4, 50, 1, 'rnd') #4 /home/grayson/html/index.php(8): require_once('/home/grayson/h...') #5 {main} thrown in /home/grayson/html/lib/thumbnail.lib.php on line 244 

정상적으로 잘 동작하다 닷홈호스팅사용중 백업으로 인해 점검을 하고난뒤 도메인도 풀리고

저런 오류문구가 뜨네요. 이유를 저쪽부분에선 건드린게 없어서 이유가 뭔지 궁금해서 여쭤봅니가. 꼭 도와주세요.

주소는 http://grayson.dothome.co.kr/">http://grayson.dothome.co.kr/ 입니다!