I am also having issues with 1.04.
Run the 1.04 installer and uninstall 1.03 w/out issue. Start the install of 1.04 and get the error shown in the attachment. If I Retry, same. If I ignore, it runs through every file for the Gizmo64 plugin. If I abort, the install stops.
I tried the ignore option and when finished, was unable to run X-Plane 11. I click the executable, the startup screen pops up for a second or two and then gone. The log.txt is of no help either (attached).
Log.txt