# App fixes flagged on Firebase Crashylitics - Mon 4th Jan, 2020

Various fixes that were mostly from Firebase. Such bug/crash reports were a definite minority of users and the app seems quite stable, which I'm happy about.

:java.lang.UnsatisfiedLinkError: couldn't find DSO to load: libhermes.so

I was seeing this error intermitently on some Android devices. I had previously enabled Hermes, but honestly I'm not sure if it was truly enabled. For now, I have disabled Hermes until I can update React Native versions, and added "SoLoader":

// https://stackoverflow.com/questions/57036317/react-native-java-lang-unsatisfiedlinkerror-couldnt-find-dso-to-load-libherm
implementation 'com.facebook.soloader:soloader:0.9.0+'

I also had an issue on Android with formatted timestamps all displaying wrongly. This was due to the bundled version of [JavaScriptCore](https://reactnative.dev/docs/javascript-environment) being old and out of date. I fixed it by updating JSC:

"jsc-android": "^241213.1.0"

And made sure gradle (in `app/build.gradle`) used JSC:

configurations.all {
    resolutionStrategy {
        force jscFlavor
    }
}

`scrollToTop={false}` prop means FlatList will stay in scrolled to position when navigating away and then returning.

I also was noticing quite a few errors on iOS when the app was trying to refresh when backgrounded, and it wasn't able to retrieve the access token for an API call.

My suspicion is that on iOS, you can [restrict the "accessibility" of a stored value in Keychain](https://developer.apple.com/documentation/security/keychain_services/keychain_items/restricting_keychain_item_accessibility). Since it was set to "when unlocked", it was not able to retrieve the token when the device was locked, and was therefore throwing a (non-fatal) error.

###### tags: `programmingjournal` `2021` `flatlist` `jsc` `gradle` `keychain` `soloader` `hermes` `firebase`