I have release apk with signed keys but it's not installing on android devices, its shows this message "The apk failed to install Error: Could not parse error string" but debugging mode apk, the app works fine.
release command
flutter build apk --release.
I did follow this question to solve it, hope it helps someone.
If you're trying to install a signed APK after using a debugging mode APK, Android will detect differences in signature, and refuse to install it.
Make sure you've uninstalled the unsigned debugging APK first from the device, and try to install again.