Video clips not working

[Penny1]

Pretty new to all this. Bought some credits to buy some videos, 2 of the 4 clips I bought kept crashing halfway through. Is this a problem with all videos or just from particular sellers? I have logged these and hope to be reimbursed. Really a pain because I don't know what will work and what will not in the meantime just throwing money down the drain. Not only that, I can't go back and try them, says I need to pay again to watch!

Thanks