UITouch.maximumForcePossible is only available in iOS 9.0+

Classes/Utility/FLEXKeyboardShortcutManager.m

@@ -165,9 +165,11 @@
                     pressureLevel++;
                 }
                 if (pressureLevel > 0) {
-                    for (UITouch *touch in [event allTouches]) {
-                        double adjustedPressureLevel = pressureLevel * 20 * touch.maximumPossibleForce;
-                        [touch setValue:@(adjustedPressureLevel) forKey:@"_pressure"];
+                    if (@available(iOS 9.0, *)) {
+                        for (UITouch *touch in [event allTouches]) {
+                            double adjustedPressureLevel = pressureLevel * 20 * touch.maximumPossibleForce;
+                            [touch setValue:@(adjustedPressureLevel) forKey:@"_pressure"];
+                        }
                     }
                 }
             }