By: Rob Purser

I’ve found that sometimes the Arduino IDE caches this info, and then doesn’t always update. Assuming you’re using windows, if you go to the AppData/Arduino15 directory, there’s a file called library_index.json. Quit the Arduino IDE, delete that file, and start it up again, and you should be all set.
On my computer, this file is at:
C:\Users
purser\AppData\Roaming\Arduino15
-Rob