LinqPad 5 with EFCore - TypeLoadException: Inheritance security rules violated by type: 'Remotion.Li


Posted a query on Stack Overflow here but didn't appear to get any traction.

Anyone have a solution to (or had a similar issues, so I can identify if its my setup or a broader issue) the following error when trying to query an EFCore DbContext from LinqPad against SQL Express..

TypeLoadException: Inheritance security rules violated by type: 'Remotion.Linq.Parsing.RelinqExpressionVisitor'. Derived types must either match the security accessibility of the base type or be less accessible.

I found a similar issue posted here but with no resolution either..

Anyone any ideas?



  • Do you have the AllowPartiallyTrustedCallers attribute set on your DbContext assembly, or any other code-access security attributes?

    If so, try removing them.
  • Hi Joe,

    Thanks for coming back to me. Nothing special with the DB context apart from inherting from IdentityDbContext.

    Just to be sure, I cloned and ran the sample code as part of the EFCore official tutorial here:

    I have modified the sample slightly, firstly to move the data stuff to a netstandard2.0 lib as the 'EF Core Driver v2.2' doesn't appear to support netcoreapp.

    I also added the 'CopyLocalLockFileAssemblies' attribute to the Data.csproj to copy all assemblies to the output folder, so I can reference the Data.dll from /data/bin/debug/netstandard2.0

    Finally I added support to the DbContext for using a parameterless constructor

    You can find the minimal sample here:

    When I create the connection with the following settings:

    It finds and loads the tables:

    However trying to execute any sort of query blows up:

    Any thoughts?


  • @sknox I chased a similar bug with core where I had three different projects:
    • BusinessEntities -- my model
    • Data Transfer Objects -- what I sent to the front end
    • core application
    I kept pointing LINQPad to my Data Transfer Objects project, because I wanted to use AutoMapper in LINQPad to see the 'actual result'. I figured if I pointed LINQPad to the dll for my BusinessEntities project next to the Data Transfer Objects it would all 'work itself out'.

    I kept receiving the same error you are seeing in your setup. Solution was to point LINQPad to the BusinessEntities project and ensure the BusinessEntities.deps.json file was generated. Lastly I told LINQPad to Restore NuGet Dependencies from the Entity Framework DbContext Connection pop up.
  • Hi @benhysell , thanks for your feedback, very much appreciated.

    In my example project ( both model/domain objects and the dbcontext are encapsulated into one project, which i'm then pointing LinqPad too the compiled assembly for that project (no need to resolve any additional libs etc).

    I also just checked and the deps.json file is getting generated/copied to the output folder alongside the DLL i'm targeting. Also tried running the 'Restore NuGet Dependencies' however just getting the same error.

    Does the minimal repro project I added above work for you by any chance? If so it means its some version/config issue on my machine and not the project/code structure.

  • I've encountered the same issue in a very basic use case:
    • Scaffold a DB context using the 'dotnet ef dbcontext scaffold ...' command
    • Build the project as a netstandard2.0 library
    • Add DB context in the Linqpad EF core driver (v2.2)
    I also tried to use the same DB context by adding it as a reference in a fresh Linqpad query which gave the same error so it doesn't seem to be a problem specific to the EF core driver.

    The only workaround for me was to revert back to an older version of EFCore (2.0.0) which uses a different version of the Remotion.Relinq package.
  • I'll try targeting that version in my sample repo shortly to see if that works. If so could just be a case of waiting until the Remotion.Relinq supports the latest EFCore 2.2
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