macOS Apple Silicon: login fails after browser authorization with SSLHandshake failed (-9836) on /token

[regiulien]

Cura Version

5.12.0

Operating System

macOS Tahoe Version 26.3.1 (a)

Printer

Ultimaker 2+ Connect (selected in Cura, but the issue does not appear to be printer-specific)

Reproduction steps

Open UltiMaker Cura on macOS Apple Silicon.
Click Sign In.
Cura opens the browser normally for the UltiMaker account login flow.
Sign-in in the browser and allow authorization.
Return to Cura.
Cura does not complete the login and remains signed out.

Actual results

After the browser authorization flow, Cura does not sign in successfully and remains logged out.
According to the Cura log, the local OAuth callback server starts correctly, but the application fails during the token exchange step with:
SSL handshake failed: -9836
The error occurs when Cura tries to POST to:
https://account.ultimaker.com/token
The log also shows the same SSL handshake error earlier at startup when Cura tries to access:
https://software.ultimaker.com/latest.json
After that, Cura reports invalid JSON / could not read response, and the login fails.

Expected results

After signing in and authorizing the app in the browser, Cura should complete the OAuth token exchange successfully and sign the user into the application.

Add your .zip and screenshots here ⬇️

I tested both Safari and Chrome.
I reset the Cura configuration folder.
I reinstalled Cura.
I also tested older versions down to 5.10.2, with the same result.
TLS connectivity from Terminal to the same UltiMaker endpoints appears to work correctly, so the issue seems specific to Cura’s internal SSL/network layer rather than general browser/system connectivity.

cura.log

[kije]

I encounter the same issue:

2026-03-27 23:03:17,975 - WARNING - [MainThread] UM.View.RenderBatch.addItem [166]: Tried to add an item to batch without mesh
2026-03-27 23:03:18,933 - WARNING - [MainThread] UM.View.RenderBatch.addItem [166]: Tried to add an item to batch without mesh
2026-03-27 23:03:20,954 - DEBUG - [MainThread] cura.OAuth2.AuthorizationService.startAuthorizationFlow [215]: Starting new OAuth2 flow...
2026-03-27 23:03:20,955 - DEBUG - [MainThread] cura.OAuth2.LocalAuthorizationServer.start [64]: Starting local web server to handle authorization callback on port 32118
2026-03-27 23:03:20,958 - DEBUG - [Thread-10 (_serve_forever)] cura.OAuth2.LocalAuthorizationServer._serve_forever [101]: Local web server for authorization has started
2026-03-27 23:03:21,890 - DEBUG - [Thread-11 (process_request_thread)] cura.OAuth2.AuthorizationRequestHandler._handleCallback [80]: Timeout when authenticating with the account server.
2026-03-27 23:03:21,975 - DEBUG - [MainThread] UM.TaskManagement.HttpRequestManager._onRequestError [394]: request[ab871f79][post][PyQt6.QtCore.QUrl('https://account.ultimaker.com/token')][timeout=5][b'client_id='...] got an QNetworkReplyError SSL handshake failed: SSLHandshake failed: -9836. The server returned: b''
2026-03-27 23:03:21,976 - WARNING - [MainThread] UM.TaskManagement.HttpRequestManager.readJSON [236]: Received invalid JSON: PyQt6.QtCore.QUrl('https://account.ultimaker.com/token')
2026-03-27 23:03:21,977 - DEBUG - [Thread-11 (process_request_thread)] cura.OAuth2.AuthorizationService._onAuthStateChanged [278]: Got callback from Authorization state. Something went wrong: [Could not read response.]
2026-03-27 23:03:21,977 - DEBUG - [Thread-11 (process_request_thread)] cura.OAuth2.LocalAuthorizationServer.stop [81]: Stopping local oauth2 web server...
2026-03-27 23:03:21,978 - WARNING - [MainThread] cura.API.Account._onLoginStateChanged [211]: Failed to login: Could not read response.
2026-03-27 23:03:21,980 - DEBUG - [MainThread] cura.OAuth2.AuthorizationService.getAccessToken [158]: No auth data to retrieve the access_token from
2026-03-27 23:03:21,980 - DEBUG - [MainThread] cura.UltimakerCloud.UltimakerCloudScope.requestHook [30]: User is not logged in for Cloud API request to https://api.ultimaker.com/cura/v1/feature_budgets
2026-03-27 23:03:22,209 - DEBUG - [MainThread] UM.TaskManagement.HttpRequestManager._onRequestError [394]: request[8cfffbd5][get][PyQt6.QtCore.QUrl('https://api.ultimaker.com/cura/v1/feature_budgets')][timeout=10][no-data] got an QNetworkReplyError Error transferring https://api.ultimaker.com/cura/v1/feature_budgets - server replied: . The server returned: b'{"errors":[{"id":"3f6bdd38-ad00-4edf-95c8-a852dbc0687b","code":"noBearerToken","http_status":"401","title":"No bearer token has been given to authenticate the request.","meta":{"error_type":"AuthError","url":"https://api.ultimaker.com/feature_budgets"}}]}'
2026-03-27 23:03:22,210 - WARNING - [MainThread] DigitalLibrary.src.DigitalFactoryApiClient.callbackWrap [74]: Digital Factory: Response is not a feature budget, likely an error: <PyQt6.QtNetwork.QNetworkReply object at 0x38bfcdb30>
2026-03-27 23:03:22,392 - DEBUG - [Thread-11 (process_request_thread)] cura.OAuth2.LocalAuthorizationServer.stop [89]: Local oauth2 web server was shut down

[HellAholic]

Unfortunately the issue is related to the digital factory and out of our hands in Cura.
As you stated, older versions are also affected which means that it's not a change in application. We do not maintain the endpoints for digital factory connection.

SSL handshake failed: SSLHandshake failed: -9836. The server returned: b''
Got callback from Authorization state. Something went wrong: [Could not read response.]
...

All indicating the API on the digital factory side as the source.
If the issue continues, please contact Ultimaker Support for assistance.

[DanielYWoo]

same here

[regiulien]

Thanks for the clarification.

It seems this is indeed related to Digital Factory connectivity.
Today the Ultimaker support page (https://support.ultimaker.com/s/) reports a banner saying:
"At this time, some users may be experiencing connectivity issues with Digital Factory."
I'll wait for some updates on their side. Thanks!

[LOCHER-21]

Same here 😑

[DanielYWoo]

all my cloud-side config cannot be downloaded for the last three days, and I can't wait anymore for my project. so I was forced to use Orca Slicer, and then I realized it's time to say good bye to Cura.

[HellAholic]

@DanielYWoo Not sure what you expect the outcome of your snarky comment would be. This is the repository of Cura, a free and open source slicer software, if you're not happy with it, feel free to move on. A service in use is not functioning and we're not maintaining that service, so we can't do much more than raise the issue with the maintainers.
Best of luck in your project. You will not be missed.

[CleykensCreates]

Same issue here on macOS Sequoia (M4 iMac) with Cura 5.11.

Browser login and localhost callback work correctly, but Cura fails on:
POST https://account.ultimaker.com/token
SSL handshake failed: -9836

Tried:

• reinstall Cura (also version 5.12)
• reset config
• different user
• different network
• OpenSSL backend workaround

Works on another computer (Sonoma 14.8).

So this confirms it’s not a local setup issue.

[sedwards2009]

The SSL related problems should be resolved now. Please try again.