YES
YES
Environment:
OS: macOS High Sierra 10.13.1
Node: 8.9.2
Yarn: 1.3.2
npm: 5.6.0
Watchman: 4.9.0
Xcode: Xcode 9.1 Build version 9B55
Android Studio: 3.0 AI-171.4443003
Packages: (wanted => installed)
react: 16.2.0 => 16.2.0
react-native: 0.51.0 => 0.51.0
I've just updated RN from 0.50.4 to 0.51.0 and this occured:
2017-12-08 14:23:03.743 [error][tid:com.facebook.react.ShadowQueue][RCTConvert.m:507] Error setting property 'start' of RCTView with tag #20: JSON value '{
x = 1;
y = "0.19";
}' of type NSMutableDictionary cannot be converted to a YGValue.
2017-12-08 14:23:03.743700+0100 HabitChallenge DEV[85512:2358649] Error setting property 'start' of RCTView with tag #20: JSON value '{
x = 1;
y = "0.19";
}' of type NSMutableDictionary cannot be converted to a YGValue.
2017-12-08 14:23:03.748 [error][tid:com.facebook.react.ShadowQueue][RCTConvert.m:507] Error setting property 'end' of RCTView with tag #20: JSON value '{
x = "0.5";
y = 1;
}' of type NSMutableDictionary cannot be converted to a YGValue.
2017-12-08 14:23:03.747804+0100 HabitChallenge DEV[85512:2358649] Error setting property 'end' of RCTView with tag #20: JSON value '{
x = "0.5";
y = 1;
}' of type NSMutableDictionary cannot be converted to a YGValue.
2017-12-08 14:23:03.765 [error][tid:com.facebook.react.ShadowQueue][RCTConvert.m:507] Error setting property 'start' of BVLinearGradient with tag #29: JSON value '{
x = 1;
y = "0.25";
}' of type NSMutableDictionary cannot be converted to a YGValue.
2017-12-08 14:23:03.765209+0100 HabitChallenge DEV[85512:2358641] Error setting property 'start' of BVLinearGradient with tag #29: JSON value '{
x = 1;
y = "0.25";
}' of type NSMutableDictionary cannot be converted to a YGValue.
2017-12-08 14:23:03.770 [error][tid:com.facebook.react.ShadowQueue][RCTConvert.m:507] Error setting property 'end' of BVLinearGradient with tag #29: JSON value '{
x = "0.5";
y = 1;
}' of type NSMutableDictionary cannot be converted to a YGValue.
2017-12-08 14:23:03.770347+0100 HabitChallenge DEV[85512:2358641] Error setting property 'end' of BVLinearGradient with tag #29: JSON value '{
x = "0.5";
y = 1;
}' of type NSMutableDictionary cannot be converted to a YGValue.
2017-12-08 14:23:03.786 [error][tid:com.facebook.react.ShadowQueue][RCTConvert.m:507] Error setting property 'end' of RCTView with tag #36: JSON value '{
x = "0.5";
y = 1;
}' of type NSMutableDictionary cannot be converted to a YGValue.
2017-12-08 14:23:03.786666+0100 HabitChallenge DEV[85512:2358641] Error setting property 'end' of RCTView with tag #36: JSON value '{
x = "0.5";
y = 1;
}' of type NSMutableDictionary cannot be converted to a YGValue.
2017-12-08 14:23:03.792 [error][tid:com.facebook.react.ShadowQueue][RCTConvert.m:507] Error setting property 'start' of RCTView with tag #36: JSON value '{
x = 1;
y = "0.19";
}' of type NSMutableDictionary cannot be converted to a YGValue.
2017-12-08 14:23:03.792357+0100 HabitChallenge DEV[85512:2358641] Error setting property 'start' of RCTView with tag #36: JSON value '{
x = 1;
y = "0.19";
}' of type NSMutableDictionary cannot be converted to a YGValue.
Simulator screenshot:

Application should run same as before
(Write what happened. Add screenshots!)
(Paste the link to an example project and exact instructions to reproduce the issue.)
It turned out to be an issue in react-native-linear-gradient. There is already a (kinda) workaround PR for this: https://github.com/react-native-community/react-native-linear-gradient/pull/243
Most helpful comment
It turned out to be an issue in react-native-linear-gradient. There is already a (kinda) workaround PR for this: https://github.com/react-native-community/react-native-linear-gradient/pull/243