I'm having problems with upgrade dnn from 3.2 to 4.8.2 . I'm getting the following error:

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.InvalidOperationException: The stored procedure 'dbo.GetPortalAliasByPortalID' doesn't exist.

Source Error:

Server Error in '/' Application.

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The stored procedure 'dbo.GetPortalAliasByPortalID' doesn't exist.

I'm facing this problem each time after upgrading a dnn site. First I've made a backup off my site. Then I uploaded the files and folders in de upgrade zip of dnn 4.8.2. Then I renamed the release.config to web.config and replaced the connection strings and the machinekeys. Then I've changed the pool to the dotnetnuke4 pool (This pool is serving more than 40 working dnn sites). I've changed the asp.net version to version 2.0. The web.config is configured with the right permissions. Still giving the same error. I've seen this error so many times i'm getting crazy of it. I've tried to remove the dnn.config in the install folder. Please help me.