Hi Jim_in_LR,
Do you by any chance have any anti-virus applications installed?
For example, Semantic endpoint protection or Microsoft Defender ATP.
If this is the case, disable your anti-virus protection and the installation should proceed normally.
If you don't have anti-virus protection installed, try booting into Safe mode and try the installation this way.
Hold down the Shift key when you boot your Mac to boot into safe mode. Release the key when you see the login window. You will see Safe Boot in the upper right corner of your screen in the menu bar. Login and try the installation this way.
I hope this helps.