Thank You Sebestian,

As per your recommendation, I decided to upgrade DNN site to Version 7.4.2 and followed the following steps to upgrade:

1. Downloaded the 7.4.2 Upgrade Package from codeplex site and unzipped it.
2. Overwrite the current site ( Test Server) folder with the package folder files.
3. Upgrade Installation started and completed successfully without any errors.

But now when I load the site I get error like DotNetNuke.Log4Net.dll Version 3.0.0.0 could not found and also could not found my custom admin menu in admin tab.

Could you please let me know whether I done any mistakes in upgrade or provide any solution to these issues.

Thank You.

Hi Sebestian,

Yes, I did then also following error is displayed on home page and home page is not loading.

Could Not Load Theme: /Portals/_default/Skins/*******/Home.ascx, Error: Could not load file or assembly 'dotnetnuke.log4net, Version=3.0.0.0, Culture=neutral, PublicKeyToken=53eb1fac7b60111f' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

And also after running TurboDNN742 scripts I get following error when i am trying to copy a page in copy page tab. 

Error: is currently unavailable. DotNetNuke.Services.Exceptions.ModuleLoadException: Cannot insert the value NULL into column 'TabOrder', table '********.dbo.Tabs'; column does not allow nulls. INSERT fails. The statement has been terminated. The 'AddTab' procedure attempted to return a status of NULL, which is not allowed.

Also, I noticed that even though upgrading to newer version, I can see CPU and Memory usage still looks at the same height as it was earlier.

Please suggest for above issues.

Thank You.