Frida Troubleshooting

Use this skill before changing hook logic when Frida itself may be failing.

First Evidence

Collect exact commands and output:

frida --version
frida-ls-devices
frida-ps -Uai

For Android:

adb devices
adb shell getprop ro.product.cpu.abi
adb shell /data/local/tmp/frida-server --version

For iOS:

frida-ps -Uai

Diagnosis Order

1. Version mismatch: host frida-tools/Python package vs frida-server/Gadget.
2. Device transport: USB, remote, emulator, jailbreak/root state, permissions.
3. Mode mismatch: spawn needed for early code, attach sufficient only after target load.
4. Runtime availability: Java.available, Java.perform(), ObjC.available.
5. Loader/module timing: class, symbol, or module not loaded yet.
6. Wrong overload/signature/address.
7. App protection or anti-instrumentation causing early exit.

Practitioner Triage

• Reproduce with a minimal script that only logs platform/runtime availability. Load the real agent only after the minimal script works.
• If CodeShare or a universal bypass "works partly", extract which hook fired and which endpoint/behavior changed before adding more bypasses.
• If traffic still does not appear after pinning bypass, check proxy trust store, certificate transparency, native TLS, HTTP/3/QUIC, alternate endpoints, backend device integrity checks, and non-HTTP protocols.
• If a hook does not fire in an obfuscated app, hook data boundaries and stack traces instead of chasing renamed classes.
• If the app exits without logs, inspect native anti-instrumentation and early lifecycle hooks with spawn mode.

Hook Does Not Fire

• Prove the code path is executed without Frida.
• Log module/class loading before installing the hook.
• For Android, enumerate overloads and class loaders.
• For iOS/Swift, enumerate symbols/modules and hook Objective-C-visible surfaces first.
• For native code, verify signature and architecture, then attach to caller/callee boundaries.

Crash After Hook

• Remove mutation and keep logging only.
• Guard null pointers and invalid ObjC/Java objects.
• Copy values inside callbacks; do not store recycled retval.
• Check string lifetime when replacing pointer arguments.
• Narrow broad hooks that fire too often or recurse.

References

Read references/error-playbook.md for common errors, likely causes, and next checks.