Issue After upgrading to Tahoe 26.2, print queues monitored by PaperCut no longer work. The print queue gets paused, and the jobs fail to print. This issue was discovered during our internal testing prior to the Tahoe 26.2 public release, and a growing number of our mutual customers have also reported it since then. Root cause This appears to be due to changes in the behavior of CUPS Sandbox restrictions, which prevent the backend (and filter) from reading/writing to the PaperCut install folder. Error messages From syslog. 2025-12-22 16:41:59.283761+1100 0x1daf61 Error 0x0 0 0 kernel: (Sandbox) Sandbox: papercut(5783) deny(1) file-write-data /Library/Printers/PaperCut/Print Provider/print-provider.log When trying to create a TCP socket from the PaperCut filter. 2025-12-15 19:50:08,403 ERROR: os_tcp_socket_create: getaddrinfo failed: nodename nor servname provided, or not known Technical details PaperCut implements print queue monitoring using a CUPS backend (and filter). CUPS backends and filters run in a security 'sandbox' which limits what they can do (such as file/folder access, create network sockets, and execute sub-processes, etc.). The PaperCut backend (and filter) relies on some of these operations, so to function correctly, our code updates /etc/cups/cups-files.conf with "Sandboxing relaxed". Until 26.2, this relaxed mode allowed us to read/write to PaperCut folders, create TCP sockets to communicate with the local PaperCut Application Server, and execute/kill sub-processes. As an alternative to the relaxed mode, we also tried "Sandboxing off", but that doesn't help either (from CUPS scheduler/conf.h). typedef enum { CUPSD_SANDBOXING_OFF, /* No sandboxing */ CUPSD_SANDBOXING_RELAXED, /* Relaxed sandboxing */ CUPSD_SANDBOXING_STRICT /* Strict sandboxing */ } cupsd_sandboxing_t; Test code We can provide a simplified version of our backend that demonstrates the issue if required Questions Has the CUPS sandbox relaxing changed? According to the CUPS man pages (cups-files.conf(5)), "Sandboxing relaxed" should still work as before. If this is the new intended behavior, what are the other options/directives we can use to relax the limitations on CUPS backends and filters?

Description: 1. When initiating the print flow via UIPrintInteractionController, and no printer is initially connected, iOS displays all possible paper sizes in the paper selection UI. However, if a printer connects in the background after this view is shown, the list of paper sizes does not automatically refresh to reflect only the options supported by the connected printer. 2. If the user selects an incompatible paper size (one not supported by the printer that has just connected), the app crashes due to an invalid configuration. Steps to Reproduce: Launch the app and navigate to the print functionality. Tap the Print button to invoke UIPrintInteractionController. At this point, no printer is yet connected. iOS displays all available paper sizes. While the paper selection UI is visible, the AirPrint-compatible printer connects in the background. Without dismissing the controller, the user selects a paper size (e.g., one that is not supported by the printer). The app crashes. Expected Result: App should not crash Once the printer becomes available (connected in the background), the paper size options should refresh automatically. The list should be filtered to only include sizes that are compatible with the connected printer. This prevents the user from selecting an invalid option, avoiding crashes. Actual Result: App crashes The paper size list remains unfiltered. The user can still select unsupported paper sizes. Selecting an incompatible option causes the app to crash, due to a mismatch between UI selection and printer capability. Demo App Crash : https://drive.google.com/file/d/19PV02wzOJhc2DYI6kAe-uxHuR1Qg15Bu/view?usp=sharing Apple Files App Crash: https://drive.google.com/file/d/1flHKuU_xaxHSzRun1dYlh8w7nBPJZeRb/view?usp=sharing

Summary: When running our iPad app on macOS (“Designed for iPad”), invoking UIPrintInteractionController intermittently fails to show a working print sheet. The same code works reliably on iPad or iOS devices and also on macOS pre 26. This regression started after updating to macOS Tahoe Version 26.0 (25A354) Steps to Reproduce: Launch the attached minimal sample on macOS (Designed for iPad). Tap “Print plain text” Expected Results: The print panel should appear and discover AirPrint printers reliably, as on iPad/iOS or previous mac versions. Actual Results: On macOS, the panel fails to appear. Mac version: macOS Tahoe 26.0 (25A354) xCode version: 26.0 (17A324) Sample Reproduction Code: struct ContentView: View { var body: some View { Button("Print plain text") { printPlainText() } .buttonStyle(.borderedProminent) .padding() } func printPlainText() { let text = "This is just a sample print" guard UIPrintInteractionController.isPrintingAvailable else { NSLog("Printing not available on this device") return } let info = UIPrintInfo(dictionary: nil) info.outputType = .general info.jobName = "Plain Text" let formatter = UISimpleTextPrintFormatter(text: text) formatter.perPageContentInsets = UIEdgeInsets(top: 36, left: 36, bottom: 36, right: 36) let ctrl = UIPrintInteractionController.shared ctrl.printInfo = info ctrl.printFormatter = formatter DispatchQueue.main.async { ctrl.present(animated: true) { _, completed, error in if let error { NSLog("Print error: \(error.localizedDescription)") } else { NSLog(completed ? "Print completed" : "Print cancelled") } } } } } Also I have added the following values to info.plist: <key>NSLocalNetworkUsageDescription</key> <string>This app needs local network access to discover AirPrint printers.</string> <key>NSBonjourServices</key> <array> <string>_ipp._tcp.</string> <string>_ipps._tcp.</string> <string>_printer._tcp.</string> </array>