parallel option of the bootMer function: warnings for parallel=no, but not for parallel=snow

Thanks for the quick response Ben!

When using parallel="multicore" I get the same warnings as when using parallel="no". However, as I am using Windows, I am not sure whether I can use multicore? (According to my task manager, all cores are used when using parallel="snow" but not when using parallel="multicore").

To check this, I also ran my code on a Mac. When running the code on a Mac, parallel="no" gives warnings as well, but parallel="multicore" and parallel="snow" do not.

For my model, warnings also seem to depend on the value chosen for set.seed(). When using set.seed(80) on Windows, parallel="no" gives warnings while parallel="snow" does not. When using set.seed(100) on Windows, neither parallel="no" nor parallel="snow" give warnings. When using a Mac, for both set.seed(80) and set.seed(100), parallel="no" gives warnings while parallel="multicore" and parallel="snow" do not.

Do you have an idea what this indicates? 

Thanks again!

Maitta