Windows 10 Pro machine -- new install of SAS 9.4. Installation proceeds normally (I simply accepted the defaults to confirm that wasn't going to be a problem), until I get to

Click next, and....installer throws the following error, and upon 'clicking OK' exits.

The log it refers to is filled with lines like the following:
INFO: ExeProc::ReadFromPipe=Standard output
java.nio.file.NoSuchFileException: C:\Users\egc\Desktop\sas.installer\hot_fix\M2K007pt.zip
at java.base/sun.nio.fs.WindowsException.translateToIOException(Unknown Source)
at java.base/sun.nio.fs.WindowsException.rethrowAsIOException(Unknown Source)
A recent JRE is already on the machine
java version "1.8.0_451"
Java(TM) SE Runtime Environment (build 1.8.0_451-b10)
Java HotSpot(TM) 64-Bit Server VM (build 25.451-b10, mixed mode)
but since 9.4 is in theory bundled with a private JRE, I'm puzzled as to what the error log is telling me -- no Java? incompatible Java? Something else?
Suggestions/pointers to the obvious most welcome.