Error on installing v4.9.0 desktop

Hello all,
Just trying to install desktop version and getting this err? it pops up right after installer program starts…
Any ideas?

Dont know why that happened. Installed launcher fine, but cant install desktop.

What operating system / version? That looks like the actual installer is failing to start, rather than Editor itself.

Yes, the installer is failing. Win10 pro / Version 4.9

Tried every version back to 4.1.0, all have same problem. The installer starts and says “Computing space” then this pops up, with a “split” button that does nothing.