uri_does_not_exist_in_doc_import

Target of URI doesn't exist: '{0}'.

The analyzer produces this diagnostic when a doc-import is found where the URI refers to a file that doesn't exist.

If the file lib.dart doesn't exist, the following code produces this diagnostic:

/// @docImport 'lib.dart';
library;

If the URI was mistyped or invalid, then correct the URI.

If the URI is correct, then create the file.