This error occurs when you are trying to install an older Paper Tiger build (< 4.1.28) in the 64 bit OS systems.
Paper Tiger latest build, i.e. >4.1.28, will support Windows Vista or Windows 7 64 bit OS. Before installing the latest version of Paper Tiger, copy your old database files and uninstall the old version Paper Tiger.
Please try to download our latest version from the below link, select the version of Paper Tiger that you are currently running and it will direct you to the Uninstall/Reinstall documentation.