AltServer on macOS 26.1 crashes during Backup step when deactivating apps on iPhone 17 (iOS 26.1), causing ServerError 2002 (USB) / Operation Error 1200 (Wi-Fi)

Description

When using AltServer.app on macOS 26.1 with an iPhone 17 running iOS 26.1, attempting to Deactivate (uninstall) an app from AltStore via USB connection consistently causes AltServer on macOS to crash as soon as the process reaches the Backup step.

AltStore then shows:

• AltServer.ServerError 2002 (when using USB)
• AltServer.Operation Error 1200 (when attempting the same over Wi-Fi — though Wi-Fi fails immediately before any backup begins)

The issue occurs every time and is fully reproducible.

Steps to Reproduce

1. Launch AltServer.app on macOS 26.1
2. Connect an iPhone 17 (iOS 26.1) via USB
3. Open AltStore on the iPhone
4. Select any installed app
5. Tap Deactivate
6. When the operation reaches the Backing up… phase
7. AltServer immediately crashes, and AltStore displays ServerError 2002

Attempting the same operation over Wi-Fi results in Operation Error 1200 immediately without reaching the backup step.

Expected Behavior

AltServer.app should successfully execute the backup step and complete the deactivation without crashing or losing connection.

Actual Behavior

• AltServer crashes instantly during the Backup step when connected via USB
• AltStore shows:
  AltServer.ServerError 2002 — Lost connection to AltServer
• When using Wi-Fi instead, the operation fails immediately with:
  AltServer.Operation Error 1200

Environment

• Mac model: Mac mini (M4, 2024)
• macOS: 26.1
• AltServer: 1.7.2 (90)
• Device: iPhone 17
• iOS: 26.1
• AltStore (on device): 2.2.1
• Connection: Type-C USB 4 40Gbps cable

Additional Context

• Issue is reproducible 100% of the time
• I can provide AltServer app logs and AltServer.app crash video if needed

Start by reproducing the Deactivate operation on the stated macOS 26.1 and iOS 26.1 environment over USB, focusing on the Backup step, and collect the AltServer logs or crash video mentioned in the issue. Compare the immediate Wi-Fi failure with the USB crash. Done means deactivation completes without a crash or the reported connection errors.