Raaaaagghhhhh

Right so i've just done two new videos and tried to transfer them from my camera to my laptop - this works fine but when i try and play the video it says its corrupt! I'm pretty sure its because of the length of the video and nothing else.....does anybody have any ideas how to fix this?? I dont want to have to keep doing short videos and editing themso they fit together! If anyone knows an answer then please let me know!!

Thanks as per usual

Princess Best xx