Notepad ++ not recognizing R language

1.Check if checkbox Enable Global foreground colour is off in settings -> -> Style Configurator -> global stylers -> global override .
2.Try changing color theme.
3.Check R's lang syntax colors in Style Configurator.

Remove R key from REBOL section in the file ‘langs.xml’ (path: user\AppData\Roaming\Notepad++\langs.xml )

Line 301 by default is:

<Language name=“rebol” ext=" r reb" commentLine=";" commentStart="" commentEnd="">

The messed up part is ext=" r reb". It should just say ext=“reb” Change that, save the file and you are all set.

See:

https://notepad-plus-plus.org/community/topic/14363/r-file-association-messed-up