With enabled sequencer polyphony must be decreased by 2 notes to get enough free RAM.

config.h

@@ -330,27 +330,27 @@
 // Teensy-3.6 settings
 #if defined(TEENSY3_6)
 # if defined(USE_FX)
-#    warning >>> With enabled FX a maximum of 14 voices is possible (due to CPU limitations)
-#    define MAX_NOTES 14
+#    warning >>> With enabled FX a maximum of 13 voices is possible (due to RAM and CPU limitations)
+#    define MAX_NOTES 12
 #    if F_CPU > 180000000
 #        error >>> Enabled FX with clockrate more than 180MHz is not useful due to RAM limitations.
 #    endif
 # else
 #   if F_CPU == 256000000
-#    warning >>> Maximum of 24 voices.
-#    define MAX_NOTES 24
-#   elif F_CPU == 240000000
-#    warning >>> Maximum of 22 voices. You should consider to use 256MHz overclocking to get a maximum of 24 voices.
+#    warning >>> Maximum of 22 voices.
 #    define MAX_NOTES 22
-#   elif F_CPU == 216000000
-#    warning >>> Maximum of 20 voices. You should consider to use 256MHz overclocking to get a maximum of 24 voices.
+#   elif F_CPU == 240000000
+#    warning >>> Maximum of 20 voices. You should consider to use 256MHz overclocking to get a maximum of 22 voices.
 #    define MAX_NOTES 20
-#   elif F_CPU == 192000000
-#    warning >>> Maximum of 18 voices. You should consider to use 256MHz overclocking to get a maximum of 24 voices.
+#   elif F_CPU == 216000000
+#    warning >>> Maximum of 20 voices. You should consider to use 256MHz overclocking to get a maximum of 22 voices.
 #    define MAX_NOTES 18
+#   elif F_CPU == 192000000
+#    warning >>> Maximum of 18 voices. You should consider to use 256MHz overclocking to get a maximum of 22 voices.
+#    define MAX_NOTES 16
 #   elif F_CPU == 180000000
 #    warning >>> Maximum of 16 voices. You should consider to use 256MHz overclocking to get a maximum of 24 voices.
-#    define MAX_NOTES 16
+#    define MAX_NOTES 14
 #   else
 #    error >>> CPU Clock below 180MHz is not supported
 #   endif