Question: +[CDSession findFirstWithPredicate:inContext:]: unrecognized selector sent to class 0x919b3c

What has changed in ios 8? It worked well with ios7. I can't get it approveed.

**UPD**

After rename methods with prefix i catch next error:

```
results = [context executeFetchRequest:request error:&error]; 
Terminating app due to     uncaught exception 'NSInvalidArgumentException', reason:
'executeFetchRequest:error: A fetch request must have an entity.

```

**UPD1**

Early happy. on simulator MR work fine without prefix, but on devices crash with : 

```
"createEntity]: unrecognized selector sent to class 0x8eafec"

```

add prefix pass this place, but crash on 

```
return [NSEntityDescription insertNewObjectForEntityForName:[self MR_entityName] inManagedObjectContext:context];`

```

with error: 

```
"CDSession" is not a subclass of NSManagedObject.

```

i think its a bug of iOs8

**UPD2**

i created simple project <http://cl.ly/2b0R2I3W3Y1P> it crashed on devices with iOS8 but working fine on simulations.

Answer: 
On devices was added CoreDuet framework with some class name like `CDSession`. i just rename this class and all working correctly now.
Use the MR\_ prefix on all your methods.