IndexOutOfRangeException error when reading all rows from table in EF Core 2.0

I have a Web API targetting .Net Core 2.0. The data source is a MySQL database, and I'm using Pomelo.EntityFrameworkCore.MySql 2.0.0.1.

I can load data from all the tables in my database except for one. I don't know why, but when I try to load all records in this database, by executing a simple:

public class MyContext : DbContext
{
    public DbSet<Condition> Condition { get; set; }
}

public class MyController : Controller
{
    private readonly MyContext _context;

    // GET: api/Sync
    [HttpGet]
    public async Task<IActionResult> GetChangeSet()
    {
        List<Condition> conditions = _context.Condition.ToList();
    }
}

I get the following error:

    _context.Condition.ToList()' threw an exception of type 'System.IndexOutOfRangeException'

    Data: {System.Collections.ListDictionaryInternal}
    HResult: -2146233080
    HelpLink: null
    InnerException: null
    Message: "Index was outside the bounds of the array."
    Source: "Anonymously Hosted DynamicMethods Assembly"
    StackTrace: "   at lambda_method(Closure , ValueBuffer )\r\n   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.InternalMixedEntityEntry..ctor(IStateManager stateManager, IEntityType entityType, Object entity, ValueBuffer valueBuffer)\r\n   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.InternalEntityEntryFactory.NewInternalEntityEntry(IStateManager stateManager, IEntityType entityType, Object entity, ValueBuffer valueBuffer)\r\n   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.InternalEntityEntryFactory.Create(IStateManager stateManager, IEntityType entityType, Object entity, ValueBuffer valueBuffer)\r\n   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.StartTrackingFromQuery(IEntityType baseEntityType, Object entity, ValueBuffer valueBuffer, ISet`1 handledForeignKeys)\r\n   at Microsoft.EntityFrameworkCore.Query.Internal.EntityTrackingInfo.StartTracking(IStateManager stateManager, Object entity, ValueBuffer valueBuffer)\r\n   at Microsoft.EntityFrameworkC
ore.Query.Internal.QueryBuffer.StartTracking(Object entity, EntityTrackingInfo entityTrackingInfo)\r\n   at Microsoft.EntityFrameworkCore.Query.QueryContext.StartTracking(Object entity, EntityTrackingInfo entityTrackingInfo)\r\n   at Microsoft.EntityFrameworkCore.Query.Internal.LinqOperatorProvider.<_TrackEntities>d__17`2.MoveNext()\r\n   at Microsoft.EntityFrameworkCore.Query.Internal.LinqOperatorProvider.ExceptionInterceptor`1.EnumeratorExceptionInterceptor.MoveNext()\r\n   at System.Collections.Generic.List`1.AddEnumerable(IEnumerable`1 enumerable)\r\n   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)"
    TargetSite: {Microsoft.EntityFrameworkCore.ChangeTracking.Internal.ISnapshot lambda_method(System.Runtime.CompilerServices.Closure, Microsoft.EntityFrameworkCore.Storage.ValueBuffer)}

This is what my Condition model looks like:

namespace Inspections.Data.Models
{
    [Table("condition")]
    public class Condition
    {
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        [Column("condition_id")]
        public int Id { get; set; }

        [Column("condition_name")]
        public string ConditionName { get; set; }

        [Column("group_id")]
        public int? GroupId { get; set; }
        [ForeignKey("group_id")]
        public virtual Group Group { get; set; }

        [Column("added_by_id")]
        public int? AddedById { get; set; }
        [ForeignKey("AddedById")]
        public virtual User AddedBy { get; set; }

        [Column("added_date")]
        public DateTime AddedDate { get; set; }

        [Column("deleted_by_id")]
        public int? DeletedById { get; set; }
        [ForeignKey("DeletedById")]
        public virtual User DeletedBy { get; set; }

        [Column("deleted_date")]
        public DateTime? DeletedDate { get; set; }

        [Column("modified_date")]
        public DateTime? ModifiedDate { get; set; }
    }
}

The exact same thing works perfectly when reading from all the other tables in the database. And the table is populated with a number of rows...

Any ideas?