Won't compile sketch: Illegal char<:> at index 93

I've just installed the latest Arduino IDE and I pointed the "additional boards manager" to the URL https://adafruit.github.io/arduino-board-index/package_adafruit_index.json.

Now my sketches won't compile. Below is the error message -- a java error in optiboot_atmega328.hex. Can anyone help? I didn't see anything like this in the forums.

I'm using a Metro board with the jumper cut/soldered to 3.3V.

Thank you!

Sam

java.nio.file.InvalidPathException: Illegal char <:> at index 93: C:\Users\sam\AppData\Local\Arduino15\packages\adafruit\hardware\avr\1.3.0\bootloaders\arduino:optiboot/optiboot_atmega328.hex
at sun.nio.fs.WindowsPathParser.normalize(WindowsPathParser.java:182)
at sun.nio.fs.WindowsPathParser.parse(WindowsPathParser.java:153)
at sun.nio.fs.WindowsPathParser.parse(WindowsPathParser.java:77)
at sun.nio.fs.WindowsPath.parse(WindowsPath.java:94)
at sun.nio.fs.WindowsFileSystem.getPath(WindowsFileSystem.java:255)
at java.nio.file.Paths.get(Paths.java:84)
at processing.app.debug.Compiler.mergeSketchWithBootloaderIfAppropriate(Compiler.java:1272)
at processing.app.debug.Compiler.compile(Compiler.java:491)
at processing.app.debug.Compiler.build(Compiler.java:125)
at processing.app.Sketch.build(Sketch.java:1117)
at processing.app.Sketch.build(Sketch.java:1097)
at processing.app.Editor$BuildHandler.run(Editor.java:1989)
at java.lang.Thread.run(Thread.java:745)
Illegal char <:> at index 93: C:\Users\sam\AppData\Local\Arduino15\packages\adafruit\hardware\avr\1.3.0\bootloaders\arduino:optiboot/optiboot_atmega328.hex

Will it compile and upload if you choose the board Uno?
What version of the IDE do you have?

A bunch of people have had IDE 1.6.x problems, including IDE crashes and bizarre compile errors, when they have an old 1.5.x/1.6.x installation. Those problems seem to be caused by out-of-date executables that the new IDE saves outside the IDE installation directory. In such cases it appears that the fix is to delete or rename the old "Arduino15" directory and re-install 1.6.x.

On Mac OS X:
/Users/username/Library/Arduino15

On Windows:
C:\Users\username\AppData\Roaming\Arduino15

Thanks, Dmjlambert. I told the IDE that I had an Arduino Uno (instead of the Adafruit Metro clone I really have) and it immediately worked fine.

I bootload all my '328Ps as an Uno to make problems like that go away.