In the Lightroom menu, go to Window->Panel and choose Effects. Or, right-click on one of the panel headers such as Tone Curve, and put a checkmark next to Effects. There is only one version of Lightroom CC. You just need to know all the shortcuts.
Right click next to one of the other tools in the right side column of the Develop Module and you will get the dropdown menu to reselect the Effect tool. It may have been deselected unintentionally.