Stack Exchange
Upgraded from 0.95.3 to 0.96.3 Cocoa Realm, getting "Property 'id' has been made optional."
Upgrading from Realm 0.95.3 to Realm 0.96.3
Application errors out inside RLMObjectStore.mm:106
Throws error stating the properties have been made optional
    (lldb) po objectSchema
DTFLogMessage {
    id {
        type = string;
        objectClassName = (null);
        indexed = YES;
        isPrimary = YES;
        optional = YES;
    }
    creationDate {
        type = date;
        objectClassName = (null);
        indexed = NO;
        isPrimary = NO;
        optional = YES;
    }
    message {
        type = string;
        objectClassName = (null);
        indexed = NO;
        isPrimary = NO;
        optional = YES;
    }
    fileinfo {
        type = string;
        objectClassName = (null);
        indexed = NO;
        isPrimary = NO;
        optional = YES;
    }
    type {
        type = int;
        objectClassName = (null);
        indexed = NO;
        isPrimary = NO;
        optional = NO;
    }
}

How can these be made non optional again i do not see anything in the documentation on how to do this. Model is configured as below:
#import <Realm/RLMObject.h>

@interface DTFLogMessage : RLMObject

@property NSString *id;
@property NSDate *creationDate;
@property NSString *message;
@property NSString *fileinfo;
@property NSInteger type;

@end

RLM_ARRAY_TYPE(DTFLogMessage)

.m file is as follows.
#import "DTFLogMessage.h"

@implementation DTFLogMessage

+ (NSString*)primaryKey
{
    return @"id";
}

@end


Realm's Objective-C docs on Optional Properties explains how to do this:

By default, NSString *, NSData *, and NSDate * properties allow you to set them to nil. If you want to require that a value be present, you can override the +requiredProperties method on your RLMObject subclass. For example, with the following model definition, trying to set the person’s name to nil will throw an exception, but setting their birthday to nil is allowed:

@interface Person : RLMObject
@property NSString *name;
@property NSDate *birthday;
@end

@implementation Person
+ (NSArray *)requiredProperties {
    return @[@"name"];
}
@end

