Let me say it again. Vortex can not install the SKSE or SKSE64 archive downloaded from Silverlock successfully. It can install the executables or it can install the scripts. Not both.
If you are modifying the archive to make it installable - that will just lead others here when they mess it up.
If Silverlock just zipped up their Script Extenders one level up, then the script extender could be installed perfectly by Vortex and any other mod manager, but because they zip up the files in a directory within a directory the best any mod manager can do is dump the script extender directory into the game root folder.
However, there's a guide in the Vortex wiki that explains how to repackage the Script Extender Archive to be an installable mod in Vortex.
However, it's caused more problems than it tries to help, because people unfamiliar with the terminology used in the guide, end up making a complete mess of the custom archive and end up with the Script Extender installed in it's own folder in the root directory, then they come in here asking for help with SkyUI errors and Mods not working because their script extender isn't working.
All the guide needs to say is
1. Drag the folder out of the script extender archive
2. Right click on the folder and pick ADD TO ARCHIVE, type in a name for it and zip it.
(Instead the guide goes through some extra confusing and unnecessary steps.)
It's much easier, and much more fool-proof to manually install the Script Extender because it requires two clicks, and a drag