GenerationError -1 / 1026

Question

Created 1w

Replies 6

Boosts 1

Participants 3

Hi,

I was using Foundation Models in my app, and suddenly it just stopped working from one moment to the next. To double-check, I created a small test in Playgrounds, but I’m getting the exact same error there too.

#Playground {
    let session = LanguageModelSession()
    let prompt = "please answer a word"
    do {
        let response = try await session.respond(to: prompt)
    } catch {
        print("error is \(error)")
    }
}

error is Error Domain=FoundationModels.LanguageModelSession.GenerationError Code=-1 "(null)" UserInfo={NSMultipleUnderlyingErrorsKey=(
    "Error Domain=ModelManagerServices.ModelManagerError Code=1026 \"(null)\" UserInfo={NSMultipleUnderlyingErrorsKey=(\n)}"
)}

I’m no longer able to get any response from the framework anywhere, even in a fresh project. It's been 5 days.

Has anyone else experienced this issue or knows what could be causing it?

Thanks in advance!

Tahoe 26.2 beta 1, Xcode 26.1.1, iPhone Air simulator 26.1

Boost

Answer 1

MB-Researcher OP

1w

This definitely sounds like a bug. Can you please file a Feedback Assistant bug report to Foundation Models Framework so we can take a look at your Mac's and Xcode's system state?

In the meantime, here are a few tactics that might help "reset" whatever's gone wrong:

Close Xcode. Restart your Mac. Open Xcode.
If that doesn't work: Go to Settings -> Apple Intelligence & Siri -> turn Apple Intelligence off. Restart your Mac. Then turn Apple Intelligence back on.

0

Answer 2

MathisGnt OP

1w

Thanks for the suggestions! I’ve tried both methods, restarting Xcode and my Mac, and toggling Apple Intelligence off and on. Unfortunately, neither resolved the issue. I’ve submitted a Feedback Assistant report with a sample project and screenshots for further investigation.

0

Answer 3

Apple Designer OP

Apple

1w

Hi Mathis!

This bug is a tricky one. Since I am not able reproduce the issue from your Feedback report sample code (thank you for the code, it really helps!), would you be able to get us a Sysdiagnose? A Sysdiagnose will let us diagnose your Mac's system state, in case something has gone wrong at the OS-level systems that Foundation Models framework relies on.

Here are the instructions: https://download.developer.apple.com/OS_X/OS_X_Logs/sysdiagnose_Logging_Instructions.pdf

The instructions come from this page under "Sysdiagnose": https://developer.apple.com/bug-reporting/profiles-and-logs/?platform=macos

If you can, attach it to your current feedback. If you need to create a new feedback report, please past the feedback ID here so I can track them together.

Thanks! - MB Researcher

0

Answer 4

MathisGnt OP

1w

Thank you for your response. The sysdiagnose should be linked to the previous feedback!

0

Answer 5

Apple Designer OP

Apple

1w

Tahoe 26.2 beta 1, Xcode 26.1.1, iPhone Air simulator 26.1

This might be the issue. Could you try updating your Xcode to 26.2 such that your Mac OS and Xcode version match?

The simulator for iPhone Air 26.1 is actually running the model on your Mac (26.2) so that version mismatch could be causing this error.

Kindly let us know if that makes any difference!

0

Answer 6

MathisGnt OP

1w

It works with Xcode 26.2 Beta! And the simulator on iOS 26.2 as well. It was indeed a version issue, because it also works on Xcode 26.1.1 with a Mac run destination. I just hadn’t tested that before. Thank you very much!

1