Is it possible to build .app file without the source code? If we just have the app installed on the iOS device and can extract .ipa


If we have an iOS app, it is a test build (enterprise build) deployed on Test Flight.

I can extract the .ipa after installing the app on the device and connecting it to iTunes.

And then I zip the .ipa file and unzip it, it shows .app file within the extracted folder of that app.

Can I use this .app file to run iOS appium scripts on simulator?

I tried doing it but it gave error -

error: Failed to start an Appium session, err was: Error: Instruments crashed on startup

info: [debug] Error: Instruments crashed on startup
at Instruments.onInstrumentsExit (/Applications/
at null. (/Applications/
at ChildProcess.emit (events.js:98:17)
at Process.ChildProcess._handle.onexit (child_process.js:820:12)
info: [debug] Responding to client with error: {“status”:33,“value”:{“message”:“A new session could not be created. (Original error: Instruments crashed on startup)”,“origValue”:“Instruments crashed on startup”},“sessionId”:null}
info: <-- POST /wd/hub/session 500 115895.509 ms - 182

Can someone please suggest some steps to launch this enterprise iOS test app on iOS simulator using appium ?