Could not scan for classes inside "C:\BitNami\wampstack-7.4.7-0\apache2\yii2up\vendor/codeception/module-yii2/src/" which does not appear to be a file nor a folder
New install got
23 package suggestions were added by new dependencies, use `composer suggest` to see details.
Package codeception/base is abandoned, you should avoid using it. No replacement was suggested.
Package fzaninotto/faker is abandoned, you should avoid using it. No replacement was suggested.
Package phpunit/php-token-stream is abandoned, you should avoid using it. No replacement was suggested.
Package phpunit/phpunit-mock-objects is abandoned, you should avoid using it. No replacement was suggested.
Generating autoload files
[RuntimeException]
Could not scan for classes inside "C:\BitNami\wampstack-7.4.7-0\apache2\Yii2new\vendor/phpunit/php-timer/src/" which does not appear to be a file nor a folder
Alright. Overall it sounds like a problem with your disk or file system. You should check SMART etc. and make backups. As for immediate solution, remove vendor and do composer install again.
I tested by installing cake and laravel, In cake I needed intl extension, in laravel I needed fileinfo.
After fixing, both cake and laravel installed. Then tried yii again, worked this time, so it probably needed one of the extensions. But no message telling me this.
Still got this however:
Package fzaninotto/faker is abandoned, you should avoid using it. No replacement was suggested.
Package phpunit/php-token-stream is abandoned, you should avoid using it. No replacement was suggested.