Upgrade error from 2.5.11 to 2.5.28

[sbw16]

I am getting an Error SQL DB function failed with error number 1062 when trying to upgrade from 2.5.11 to 2.5.28. I hope someone can help me.

[Webdongle]

Make a backup
In /administrator/components/com_admin/sql/updates/mysql ... delete ALL THE 1.7* sql files
Then try

If no avail
Download the update file
Unzip
Remove those files
Zip up the remaining files
Upload to /tmp
Then try again

[sbw16]

Thank you so very much for your reply. I did download the update file, and when I checked back on the site, it appears that I have the 2.5.28 version now....not sure why. I didn't do anything else.

[sbw16]

Now the site is saying to reinstall the upgrade so I will try your recommendation....I also noticed that there is an unsolicited ad on the homepage.....argh!

[Webdongle]

... I also noticed that there is an unsolicited ad on the homepage...!

You could have been hacked

Please http://forum.joomla.org/viewtopic.php?f=621&t=582860

And what is your url ?

[sbw16]

I know the site was hacked but Godaddy SiteSecurity was supposed to clean it and install ongoing security. Then I was supposed to do the upgrade, which brings me to my current situation.
The URL is southernillinoismuseums.org

[Webdongle]

I know the site was hacked but Godaddy SiteSecurity was supposed to clean it ...

They didn't do a very good job of cleaning the site

... I also noticed that there is an unsolicited ad on the homepage...!

You need to clean the site properly before you update. Please see and follow the instructions on http://forum.joomla.org/viewtopic.php?f=621&t=582854