I have spent days creating my AMV using the anime:

Diabolik Lovers.

ALL files are wmv and when i finished, one video I used cut out with a grey background and yellow mark, only on that particular video.

I have a Windows 8 and the file used hasn't been deleted. 

I have taken them from Youtube. Downloaded AND converted into wmv, randomly it then cut out. My file that is playing up, is called :

Diabolik Lovers ANIME Opening HD.2, the weird part is that it was fine until a few moments ago, after hours of perfect use it then and ONLY THEN decides to cut out!

HELP PLEASE!!! I DON'T WANT TO CUT IT ALL AGAIN!