laravel Unable to prepare route … for serialization. Uses Closure

Question

When I clear caches in my Laravel 5.2 project, I see this error message:

[LogicException] Unable to prepare route [panel] for serialization. Uses Closure.

Answer 1

If none of your routes contain closures, but you are still getting this error, please check

routes/api.php

Laravel has a default auth api route in the above file.

Route::middleware('auth:api')->get('/user', function (Request $request) {
    return $request->user();
});

which can be commented or replaced with a call to controller method if required.