Just did some heavy editing on an hour long video and when I tried to save it for high definition display, I got the error "There isn’t enough memory available to save this file. Try saving it at a lower resolution."  I have ample space on my computer, and do this type of thing with 3+ hour videos often.  My graphics card drivers are up to date.  Any ideas?

Specs
Operating System
    Windows 10 Pro 64-bit
CPU
    Intel Core i7 4790 @ 3.60GHz    29 °C
    Haswell 22nm Technology
RAM
    16.0GB Dual-Channel DDR3 @ 666MHz (9-9-9-24)
Motherboard
    MSI Z87-G45 GAMING (MS-7821) (SOCKET 0)    36 °C
Graphics

    4095MB NVIDIA GeForce GTX 970 (EVGA)    51 °C
Storage
    149GB TOSHIBA MK1652GSX (SATA)    28 °C
    698GB Western Digital WDC WD7500BPKX-22HPJT0 (SATA)    30 °C