The back end of the project is Laravel, the front end Vue, the front end separation project.
Error: NO ‘Access-Control-Allow-Origin’; error: NO ‘Access-Control-Allow-Origin’;
The same system other pages are OK, so exclude configuration reasons.
The problem was discovered: the back-end page had introduced a trait whose name did not conform to the PSR-4 auto-load specification, and the error disappeared when the name was changed.
Does not comply with PSR-4 autoloading standard. It will not autoload anymore in Composer v2.0.in phar:///usr/local/bin/composer/src/Composer/Autoload/ClassMapGenerator.php:201