[visual studio] installer 'install'/'uninstall' not available

Try to "build"/"Rebuild" installer project in solution.

symfony 404 not found on file upload

be sure you changed "upload_max_size" in needed php.ini, added "client_max_body_size 100m;" in case nginx.conf, and do not forget to restart all php, nginx, apache2 daemons, or better reboot system.

twig unrecognized field 0

because you forget add parameter as associated array, for example

findOneBy(['providerReference' => $reference])

, not (['provideReference', $reference])