UE 4.27 offline build dependencies? Successful build, but missing dlls to run

I’m able to successfully build on a system with internet access and run UE 4.27 release without issue. When I download the source, zip and move to an offline machine, I can build it without errors, but I can’t run it. First was directX, which I solved by copying the xinput1_3.dll to the bin directory.

Now I’m getting a message: Plugin ‘OpenXR’ failed to load because module ‘OpenXRHMD’ could not be loaded…

Is there a list of dependencies I can look to make sure are loaded on the system before I try to run UE 4.27 ? My google-fu has turned up empty. Also, I cannot find any installer for OpenXR libs. The Kronos site has announcements and sample code, but no dll download.

Thank you for your help, and your patience. I did search for these answers before posting, but I may have missed the obvious.

Take care,

-ctj