Unhandled JS Exception:undefined is not an object(evaluating 'n.Mode')

[ctwol]

Hi,

I have a project build upon Expo, but when i run expo build:ios
(have all the certification, and running well on expo client)

after i have the IPA link, and downloaded to my iPhone,

the app just stopped working and display:
“Unhandled JS Exception:undefined is not an object(evaluating ‘n.Mode’)”

can somebody help me on this?

[adamjnav]

Hey @ctwol,

Does the stack trace point to anything in particular? You can try running expo start --no-dev --minify to recreate the production environment JS bundle.

Cheers,
Adam

[ctwol]

Hello,

Thanks for replying!

The situation is that: the app works fine when i expo start(both iOS and Android)

Then, when I ran “expo build:iOS”

Downloaded, add to iPhone by Apple configurator2

When I open the app, after loading screen
It shows

(Btw, I also ran “expo start --no-dev --minify”, and the app works fine in both emulator and real device). Also, when I trying to “expo build:ios -t simulator”, the app stopped in emulator like the picture above

[adamjnav]

Are you able to create an .apk file and test it? If so, digging into the device logs via USB debugging and Android Studio will provide a lot more insight.

[ctwol]

Hi thanks for reply:

1, I’m able to generate .apk file and it works in both android emulator and real device

2, so everything works fine but its just when i generate the iPA file, the errors comes out. And when search the code ‘n.MODE’ within project folder, nothing being found.