contract D { fallback(bytes memory) external returns (bytes memory) {} } contract E { fallback(bytes memory) external returns (bytes calldata) {} } contract F { fallback(bytes calldata) external returns (bytes calldata) {} } // ---- // TypeError 5570: (57-71): Fallback function either has to have the signature "fallback()" or "fallback(bytes calldata) returns (bytes memory)". // TypeError 5570: (134-150): Fallback function either has to have the signature "fallback()" or "fallback(bytes calldata) returns (bytes memory)". // TypeError 5570: (215-231): Fallback function either has to have the signature "fallback()" or "fallback(bytes calldata) returns (bytes memory)".