I have installed, but have not been able to run 3DXchange 6.3 Pipeline. I have been able to update and run iClone and CC, but no luck with 3DX. I have done a fresh install, but that didn't do any good either. What happens is that on launch there will be three instances of 3DXchange showing in the Task Manager, but the user interface doesn't show. It is impossible to kill those instances, one has to reboot.
I had it once happen with iClone, and I fixed that be changing the temp directory to the default, but there are no settings like that for 3DX.
Fortunately, I have a laptop with the full install files for an older version of the of 3DX, and I was able to install from that, giving my 3DX 6.1 for the moment. But I do not understand why the upgrade to 6.3 didn't work. Over the years 3DX has given me very few problems.