Why can't I save my render????

[fourthand11]

I've had this problem when saving across a network. I started saving to my C: and haven't had the problem since.

[YoyoBoy]

I'm having this problem too. I have my 3600x1800 render in the VRay Frame Buffer and I'm trying to save. It won't let me save it in ANY format and RAW (as was mentioned as a solution) is not an option.

????