When upgrading to Update 72, I get some stacktraces. Something related to SiteDefinition.

There is already an open DataReader associated with this Command which must be closed first.

[InvalidOperationException: There is already an open DataReader associated with this Command which must be closed first.]
   System.Data.SqlClient.SqlInternalConnectionTds.ValidateConnectionForExecute(SqlCommand command) +5332771
   System.Data.SqlClient.SqlConnection.ValidateConnectionForExecute(String method, SqlCommand command) +51
   System.Data.SqlClient.SqlCommand.ValidateCommand(String method, Boolean async) +155
... 

[TypeInitializationException: The type initializer for 'EPiServer.Web.SiteDefinition' threw an exception.]
   EPiServer.Web.SiteDefinition.get_Current() +0
   EPiServer.Initialization.XFormsInitialization.Initialize(InitializationEngine context) +154
   EPiServer.Framework.Initialization.<>c__DisplayClass5.b__4() +19
   EPiServer.Framework.Initialization.ModuleNode.Execute(Action a, String key) +43

...

When reverting all files updated during the upgrade, the site cannot start because obviously the database now has a newer version.

[NotSupportedException: The assemblies has not been updated to work with the current database version for database 'EPiServerDB'. Current database version is '7020.0', but the assemblies only supports '7019.0'.]

So what to do now...? Please advice.