Invalid usage of `RuntimeEvent`

Question

I am a beginner learning the substrate framework, So am actually following the documentation on the substrate website where it references the use of macros in a custom pallet, after implementing all the code, am facing some import errors, due to the lines posted below.

pub use pallet::*;
#[frame_support::pallet]
pub mod pallet {
    use frame_support::pallet_prelude::*;
    use frame_system::pallet_prelude::*;

Below is the complete error trace

    Compiling pallet-template v4.0.0-dev (/Users/mac/Desktop/pallet-identity/pallets/template)
  error: Invalid usage of RuntimeEvent, `Config` contains no associated type `RuntimeEvent`, but enum `Event` is declared (in use of `#[pallet::event]`). An RuntimeEvent associated type must be declare on trait `Config`.
    --> /Users/mac/Desktop/pallet-identity/pallets/template/src/lib.rs:11:1
     |
  11 | #[frame_support::pallet]
     | ^^^^^^^^^^^^^^^^^^^^^^^^
     |
     = note: this error originates in the attribute macro `frame_support::pallet` (in Nightly builds, run with -Z macro-backtrace for more info)

  error[E0432]: unresolved import `pallet`
   --> /Users/mac/Desktop/pallet-identity/pallets/template/src/lib.rs:7:9
    |
  7 | pub use pallet::*;
    |         ^^^^^^ help: a similar path exists: `frame_system::pallet`

  For more information about this error, try `rustc --explain E0432`.
  error: could not compile `pallet-template` due to 2 previous errors

Answer 1

Outdated ~~Check your Cargo.toml. I think you missed the frame-support dependency.~~

---

After you updated the detail.

The main error is:

error: Invalid usage of RuntimeEvent, `Config` contains no associated type `RuntimeEvent`, but enum `Event` is declared (in use of `#[pallet::event]`). An RuntimeEvent associated type must be declare on trait `Config`.

So, follow the message to add the RuntimeEvent field back to your Config trait.

type RuntimeEvent: From<Event<Self, I>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;

---

After taking a look at your source code.

I believe you have updated your Substrate version.

There is a breaking change.

Config::Event was renamed to Config::RuntimeEvent.

https://github.com/paritytech/substrate/pull/11981.

---

error[E0432]: unresolved import `pallet`

This error is because the macro will generate a mod pallet. But another error occurred while expending/executing the macro, so the mod pallet can not be generated. Thus, it reports can not find the pallet