That’s not a critical issue. It sounds like you have a fully working install.
(But you should use the latest Dynare 4.5, not 4.5.0. Latest is 4.5.7 if I remember right.)
I’m not sure what the source of that OptiToolbox issue is, but given OptiToolbox is no longer supported I ought to remove all dependence on it.
You ought to install Gurobi or similar to get a decent solver.