Two Possible reasons for this issue ..

1. Either pending reboot

2. Conflict with existing Driver or version of VMware Converter

You may try the following ...

1. Reboot the Machine and retry the installation

2, If there is already an existing version of Converter installed, try to uninstall the VMware Converter, reboot the machine and install VMware Converter 6.1.1

let us know how it goes ..