Exception thrown while attempting to evaluate the LINQ query parameter expression 'value(Finbuckle.MultiTenant.EntityFrameworkCore.FinbuckleEntityTypeBuilderExtensions+ExpressionVariableScope).Context.TenantInfo'

[MarcoGaribaldi]

Hello everyone,

hope someone can help me with the following problem. I am working on an app where the backend is based on the dotnet-webapi-starter-kit. When the application starts and the ApplicationDbSeeder class is executed, I get an error in the SeedRolesAsync method when the following code is executed

private async Task SeedRolesAsync(ApplicationDbContext dbContext)
{
    foreach (string roleName in Roles.DefaultRoles)
    {
        if (await roleManager.Roles.SingleOrDefaultAsync(r => r.Name == roleName)
            is not { } role)
        {
			etc...

This is the error I get:

"An exception was thrown while attempting to evaluate the LINQ query parameter expression 'value(Finbuckle.MultiTenant.EntityFrameworkCore.FinbuckleEntityTypeBuilderExtensions+ExpressionVariableScope).Context.TenantInfo'. See the inner exception for more information."

The inner exception is:

"Object reference not set to an instance of an object."

Finbuckle is configured this way:

internal static IServiceCollection AddMultitenancy(this IServiceCollection services, IConfiguration config)
{
    return services
        .AddDbContext<TenantDbContext>((p, m) =>
        {
            // TODO: We should probably add specific dbprovider/connectionstring setting for the tenantDb with a fallback to the main databasesettings
            var databaseSettings = p.GetRequiredService<IOptions<DatabaseSettings>>().Value;
            m.UseDatabase(databaseSettings.DBProvider, databaseSettings.ConnectionString);
        })
        .AddMultiTenant<FSHTenantInfo>()
            .WithClaimStrategy(FSHClaims.Tenant)
            .WithHeaderStrategy(MultitenancyConstants.TenantIdName)
            .WithQueryStringStrategy(MultitenancyConstants.TenantIdName)
            .WithEFCoreStore<TenantDbContext, FSHTenantInfo>()
            .Services
        .AddScoped<ITenantService, TenantService>();
}

I have noticed that the same error happens whenever LINQ code is executed. As an example, SeedRolesAsync is called by the following method

public async Task SeedDatabaseAsync(ApplicationDbContext dbContext, CancellationToken cancellationToken)
{
    await SeedRolesAsync(dbContext);
    await SeedAdminUserAsync();
    await seederRunner.RunSeedersAsync(cancellationToken);
}

If I comment out SeedRolesAsync the same error happens in the SeedAdminUserAsync method when this line is executed

    if (await userManager.Users.FirstOrDefaultAsync(u => u.Email == currentTenant.AdminEmail)
        is not { } adminUser)

The same happens if I do the following

    if (!userManager.Users.Any())
        return;

Any idea on what may be the problem?