crash on opening serial port

java.lang.NumberFormatException: For input string: "rm"
at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:2043)
at sun.misc.FloatingDecimal.parseFloat(FloatingDecimal.java:122)
at java.lang.Float.parseFloat(Float.java:451)
at cody.grbl.GrblStream$Reader.run(GrblStream.java:216)
at java.lang.Thread.run(Thread.java:745)
AL lib: (EE) alc_cleanup: 1 device not closed