CANNOT INSTALL .pkg file on MAC

[ICanSpinIt]

I am running the latest Mac OS 10.15.6 

I have tried to install all /any scripts/add-ins from the store and the very last installation screen on the installer shows the "failed to install contact the software manufacturer" 

I'm guessing this is a setting on my computer that is not allowing the file to be installed to the scripts/add-ins folder? 

Is there a fix or a manual install work around?

Thanks in advance!

[ICanSpinIt]

I have done a manual clean uninstall, that has not fixed the issue either

[ICanSpinIt]

Does Anyone know why?! I have read and read, cannot find one solution