NSManagedObjectModel error

[eugeniobaglieri]

while running the example project, I get an infinite list of these errors in console log:

[error] error: The fetch request's entity 0x2819d0a50 'Device' appears to be from a different NSManagedObjectModel than this context's
CoreData: error: The fetch request's entity 0x2819d0a50 'Device' appears to be from a different NSManagedObjectModel than this context's
[error] error: The fetch request's entity 0x2819d09a0 'Event' appears to be from a different NSManagedObjectModel than this context's
CoreData: error: The fetch request's entity 0x2819d09a0 'Event' appears to be from a different NSManagedObjectModel than this context's

How can I resolve?

[eugeniobaglieri]

I found only a thread on SO bit without solution. Ma cos’è is a “working” clone of the Example project

…

-- Eugenio B.

Il giorno 11 nov 2018, alle ore 14:24, David DelMonte ***@***.***> ha scritto: I'm not affiliated with the project, but you might want to post your code, your model and store/fetch. This also may be better served by posting the question on Stack Overflow. If you search there, with a tag of "Seam 3", you may find others who have the same question. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub, or mute the thread.

[lvandal]

I get the same error as well.

[lvandal]

Perhaps this fix could be applied here? superk589/DereGuide#24

[DJ-Glock]

I believe this issue happens with all projects that use Seam3. It looks like it happens because Seam3 does some work in a background thread. Not sure if it can be solved. In my project these warnings did not cause any issues so far.

[hyerra]

I wonder if this is due to the fact that we are adding some extra backing store attributes that might cause the model to change. Maybe if we had the user manually add this into the model, this message wouldn't show.

[mklybor]

Wondering if this issue has been addressed in the two updates that were merged recently. I just cloned seam3, added it to my app, and got the same nsmanagedobjectmodel error.

[mklybor]

got a fix. @hyerra had diagnosed right. it was fetching into the backing context using a fetch request that contained an entity description from (I guess) the view context.

my fix is to create a copy of the fetch request using the entity from the backing context with the same entity name as in the original fetch request:

func executeInResponseToFetchRequest(_ fetchRequest:NSFetchRequest,context:NSManagedObjectContext) throws ->[Any] {

    let newFetchRequest = fetchRequest.copy(with: nil) as! NSFetchRequest<NSFetchRequestResult>
    let entityName = newFetchRequest.entityName
    let entities = backingMOC.persistentStoreCoordinator?.managedObjectModel.entitiesByName
    let entity = entities![entityName!]
    newFetchRequest.entity = entity
    
    let resultsFromLocalStore = try self.backingMOC.fetch(newFetchRequest)

[brianminor]

@mklybor any chance you can share a little more on how you're doing it? I'm newer to CoreData and having the same issue.

[mklybor]

Look at my branch for the fix:

https://github.com/mklybor/Seam3/tree/fix_model_error

there was a fetch request that had an issue that was causing the warning msg.

this should get rolled into the master.

[daviddelmonte]

Has this been rolled into the master? Thanks