graphics are suddenly blacking out large sgments of my screenin both old saves and new sly started games ??

Please add more Info's.

Was this a one-time error and you're just curious what happend, is this a recurring problem?

What are you system-specs, what version do you use, do you use any mods,...?

intel 5930k,evga1080ti ftw 16 gigs of dram windows 10 64 home,fractal blocking occurs in enclosed intense visuals but can appear anywhere, the priginal was in Dallis suite aboard lady vengeance??

Hmm, there's a known error like this but it only occured with radeon cards.

If this is similar problem the cause is/are shader/shade-settings, try to turn it off ingame/card-settings, if this solve the problem you can try to finetune it to find the right settings.
If the shader is not the problem you should try if you have problems with other games too, worst case is that your card is about to die.

Sorry that i can't help more, good luck.