Hi there, please forgive me I have not used DNN before.
So I am attempting to move a DNN site from Net Logistics to my Windows SBS2011/IIS7 Server.
Attempting to follow many instructions out there.
I restored a backup of the database to my SQL server and dnn install to a new directory within the wwwroot folder, and converted it to an application. I have updated the connections to the database and this seems to be all. The issue I am encountering is and ! in a red triangle with

An error has occurred.
An error has occurred.

and this Default.aspx?tabid=36&error=Object+reference+not+set+to+an+instance+of+an+object.&content=0

I have no idea what version the ddn is, all I can say the site was setup around 2006.

Any assistance would be greatly appreciated.

Thank you

Look in the Versions table in the database. The last row is the last version installed.

Check the file permissions for the web directory. IIS must be able to read and write files.

Double check the db connections, and also make sure that the db user has dbo privileges.