It was denied when you tried to install opptimizer_1.5.2. Therefore you don't have the modules installed.

Try to delete signature.local which should be located same as your opptimizer file and give it a kick again. It should work.

If not, uninstall opptimizer_1.5.1, delete signature.local, reboot (?) and then install opptimizer_1.5.2 then opptimizer-ui.

The method above works for me. But there may be some better ways from others to solve this.