How to solve the problem when updating composer?

Question

PHP

I update composer this way: ...\php.exe ...\composer.phar update An
error like: [RuntimeException] Could not scan for classes inside 'project folder'\vendor/phpunit/php-file-iterator/src /" which does not appear to be a file nor a
folder

Answer 1

1. backup the vendor, composer.json, composer.lock folders
2. delete the vendor folder in your project.
3. run composer install (a new unbroken vendor will appear)
4. run composer update
If something went wrong, don't lose the backup)

Answer 2

Obviously the file system is broken.