When the installation of a consumer fails because of
wrong file or directory rights (mostly missing write
for others/all) the installer shows the input formular
for admin password...
This is a critical bug, we should perform a file check
before we start the installation. If this fails we
should display a link to the Pre-Check screen where
more information can be found.
If no required directory can be found that is not
writable we can start the installation.
Maybe do complete rollback if a failure occurs.