Hello there.
Most plugins rely on the .js file having its original name in order to read the plugin parameters. Mine are also like this, so it would've failed loading very early in the load process, likely without throwing any crash errors, and simply would've acted as if the plugin wasn't installed at all. That means the error you were getting from the Visu plugin was correct, that function is not a function - because the plugin which defined it as a function was not loaded :)
For what it's worth, there is a way to make plugin parameters work when renaming the .js file, but it needs to be written in a specific way to allow that, and as it was simply the easier thing to do, I chose not to do that, like most people.
~Ramza