Win 10, after april 14 update unuseable. RefreshWindowsTool.exe won't open, MediaCreationTool20H2.exe unuseable

refreshwindows tool won't open event viewer log below :

Faulting application name: refreshwindowstool.exe, version: 10.0.16217.1, time stamp: 0x57a396f7
Faulting module name: clr.dll, version: 4.8.4341.0, time stamp: 0x6023024f
Exception code: 0xc00000fd
Fault offset: 0x004d4e0a
Faulting process id: 0x14a0
Faulting application start time: 0x01d73c8e03a89894
Faulting application path: c:\6bf104118cbaacc387b91adc\refreshwindowstool.exe
Faulting module path: C:\Windows\Microsoft.NET\Framework\v4.0.30319\clr.dll
Report Id: 5e5f94a6-512e-4800-a90a-6b72a959809e
Faulting package full name: 
Faulting package-relative application ID: 

And the mediacreationtool is unuseable it opens, but the font rendering is all messed up. Accept and Decine buttons invisible.

This is after performing a reset and keeping my personal files.

Any help ? (anywhere better to ask?)

A reset was performed because lots of websites were failing and I was getting a lot of runtime exceptions in desktop apps that had never been a problem. Checked the event log and was getting similar errors to the above.

Was working perfectly until the april 14th update.

Ran the .net repair tool, did nothing. Attempted to install the latest .net runtime, didn't let me.