EF 6.1.3 exception - Unable to cast object of type 'System.Data.Entity.Core.Objects.ObjectContext' to type 'System.Data.Entity.DbContext'

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When I instantiate a DbContext, I sometimes, but rarely am getting this exception. (Like once a week.)

[InvalidCastException: Unable to cast object of type 'System.Data.Entity.Core.Objects.ObjectContext' to type 'System.Data.Entity.DbContext'.]
   System.Data.Entity.Infrastructure.Interception.DatabaseLogFormatter.get_Context() +86
   System.Data.Entity.Infrastructure.Interception.DatabaseLogFormatter.Opened(DbConnection connection, DbConnectionInterceptionContext interceptionContext) +88
   System.Data.Entity.Infrastructure.Interception.InternalDispatcher`1.Dispatch(TTarget target, Action`2 operation, TInterceptionContext interceptionContext, Action`3 executing, Action`3 executed) +373
   System.Data.Entity.Infrastructure.Interception.DbConnectionDispatcher.Open(DbConnection connection, DbInterceptionContext interceptionContext) +503
   System.Data.Entity.SqlServer.<>c__DisplayClass1.<Execute>b__0() +18
   System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute(Func`1 operation) +234
   System.Data.Entity.Core.EntityClient.EntityConnection.Open() +318

[EntityException: The underlying provider failed on Open.]
   System.Data.Entity.Core.EntityClient.EntityConnection.Open() +738
   System.Data.Entity.Core.Objects.ObjectContext.EnsureConnection(Boolean shouldMonitorTransactions) +167
   System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction(Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess) +60
   System.Data.Entity.Core.Objects.<>c__DisplayClass59.<ExecuteStoreCommand>b__57() +118
   System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute(Func`1 operation) +206
...
...

The DbContext that I'm instantiating inherits from a base DbContext that I wrote. In that constructor I do this:

            this.Database.Log = s => this.sqlLogger.Debug(s);
            this.Database.ExecuteSqlCommand(Resources.SqlServerConnectionInit); // throws here

I'm using EF 6.1.3. When I look at the Microsoft code, in DatabaseLogFormatter.cs, I just totally don't see how it's possible for this exception to happen. I just don't see how that variable could actually be a System.Data.Entity.Core.Objects.ObjectContext.

This code is being run in a web app. And once this exception happens, it will continue to happen - always - until I restart the web server. Restarting the database server doesn't fix anything.

I have found absolutely nothing on the internet about this.

FYI: SQL Server is the database server.

entity-framework-6 entity-framework sql-server
1 Answers

Please pay attention to exception :

Unable to cast object of type System.Data.Entity.Core.Objects.ObjectContext to type System.Data.Entity.DbContext

Both are classes inside EntityFramework.dll, available for +6.x version. You called both in your project which creates a baffling condition. Next exception is the result of first one, The underlying provider failed on Open. In this way, it can't access data.

DbContext vs ObjectContext

Shortly, DbContext is just a wrapper around ObjectContext. ObjectContext is the top-level object, while DbContext instance represents a combination of the Unit Of Work and Repository patterns, Although DbContext is conceptually similar to ObjectContext.

Solution: Check the (configuration including context) parts of your code where a mismatch exists in order to avoid casting.

user_17439970
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