Right-clicking on a folder in the World Outliner and selecting "rename" in the drop down menu is not functioning on Macs running El Capitan or Sierra.
NOTE: The folder can be renamed by selecting, highlighting, and waiting for text to turn blue OR by pressing F2. However, some users report these workarounds are not working.
Not a regression.
Head over to the existing Questions & Answers thread and let us know what's up.