Strange error during install: Your database has been found and is identified as: None

I had moved my web site and database to two new servers, and in the process I also changed the login name in the new database to something that felt better just then.

Everything went fine when I restored the database from my backup, “- Very smooth”, I thought.

After web.config was updated I tried to launch my site, but all I found was an error that said:

“Invalid object name 'umbracoUser'.”

I found a posting in the forum that the installation should be ran again to fix this issue.

Well, I set the “umbracoConfigurationStatus” to nothing (“”) in web.config and followed the installation steps.

In the “Detect” step I was puzzled by the message “Your database has been found and is identified as: None”.

I just knew there where a database in there, I don’t want to overwrite it with a clean one! What's this?

Then I noticed that most of the tables in my database had the prefix "my_OLD_user_name" and therefore couldn't be found if my new user had an other default schema... If your user isn't DBO, the default schema will most likely be the same as the username ("my_NEW_user_name" in this example).

I tried a lot of weird things but the thing that solved the problem was this:

I opened up my new user in SQL Server Management Studio under my_NEW_DB >> Security >> Users >> my_NEW_user_name, (right-click) >> Properties.

Under "Default Schema" click the button "[...]" then the "Browse" button in the next window, select the schema that your tables are prefixed with, in this example "my_OLD_user_name", click OK to get out of there and then reload the "Detect" step in the installer.

This solved it, now the installer found the correct tables and identified my database as "v3" - Nice!

My guess is that the schema change will solve the initial error “Invalid object name 'umbracoUser'.”, without going throw the installation, since the symptoms are similar; The schema prefix does not match the users default schema...