Compiles without issue with 1.6.13, ill download the newer IDE and try again.
Update: compiled on 1.8.2 also...
My testing was get a fresh copy of marlin
enable RGB_LED
download 1.8.2 ardunio ide.
set board type to mega2560
hit verify..
What board did you select and what does you full configuration.h look like?
Also if you got to tools|board|manager change the type to updatable, is there anything that needs updating?
Update: compiled on 1.8.2 also...
My testing was get a fresh copy of marlin
enable RGB_LED
download 1.8.2 ardunio ide.
set board type to mega2560
hit verify..
What board did you select and what does you full configuration.h look like?
Also if you got to tools|board|manager change the type to updatable, is there anything that needs updating?