You may try uninstalling it first using these commands

First, open xterminal as "root"

Then, type apt-get purge opptimizer

Wait until you see the #. Next, apt-get purge opptimizer-ui

After you successfully uninstalled both of them try installing them again in the order as what DeepBlue said. Then try running OPPtimizer and do the tweak. Hope it helps