The most effective solution is to stop using the original Cydia Impactor. The developer has not updated it since 2019. Instead, use AltStore, Sideloadly, or SideStore.
Once you switch to Sideloadly, you will never see line 37 again.
For developers and the curious, here is what is actually happening inside the ipa.cpp file. cydia impactor error line 37
The original source code looks something like this (simplified):
// Line 30-40
json teams = result["teams"];
assert(teams.is_array());
assert(teams.size() == 1); // <-- THIS IS LINE 37
result is the JSON payload sent back from Apple’s authentication server. In 2019, Apple changed the structure of this payload. Instead of a clean array with one team, they began returning: The most effective solution is to stop using
Because Saurik has not updated the code, the assert(teams.size() == 1) fails. The program has no instructions for "what to do if the array size is 0 or 2," so it throws the assertion error and crashes.
The error on "line 37" generally points to a runtime error or a path not found issue. Once you switch to Sideloadly, you will never
If you are an iOS enthusiast who enjoys sideloading apps (like ++ apps, emulators, or custom IPA files), you have likely encountered the dreaded Cydia Impactor Error: "Line 37" . This error has become a rite of passage for sideloaders, often appearing at the worst possible moment—right when you think your app is about to install.
Understanding this error is the first step to fixing it. Below, we break down exactly what "line 37" means, why it happens, and the most reliable solutions.