Trying to Upgrade to 1.4 but getting "Site Down for Maintenance"

[Alpdog14]

I have backed up all the databases and files and downloaded the full version of 1.4 to upgrade my CMSMS 1.3.1. I copied all the files over my old ones on my server. I then followed the instructions to delete the "install" folder after the files uploaded and now when I go to my site all I get is a "Site down for maintenance." message. How do I get back my website design with the new version installed. Please help.

[alby]

I then followed the instructions ...

what is the document?
In Upgrading there is:
4. Navigate to /install/upgrade.php. That automatically makes any necessary changes in the database.

This clean file tmp/cache/SITEDOWN

if upgrade not clean, go in admin and in General Settings Clean Cache or delete this file via FTP

Alby