net framework 3.5 windows 10 0x800f081f wsus

Решение:
DISM /Online /Enable-Feature /FeatureName:NetFx3 /Source:d:\sources\sxs /All /LimitAccess

(replace D: with your mounted Win10 ISO)

https://superuser.com/questions/946988/cant-install-net-3-5-on-windows-10