Held keys send invalid message to Synergy 1.4 client

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• I have done the sanity checks, and my issue persists.

Deskflow version info

Deskflow: 1.26.0.0 (760e3b99) Qt: 6.11.1 System: Arch Linux Session: KDE (wayland)

Build types

Community package (apt, dnf, pacman/aur, brew, etc.)

Deskflow configuration

• Windows XP x86 client (Synergy 1.4.9)
• Arch Linux server (Deskflow 1.26.0)

What steps will reproduce the problem?

1. Connect the machines; Network protocol set to (X) Synergy, with encryption disabled.
2. Hold down a keyboard key.
3. Synergy disconnects and/or crashes; reconnecting soon after.

Log output

Show log

Server:

[2026-08-15T11:30:20.544] IPC: client "tinyidiot" has disconnected
[2026-08-15T11:30:20.544] INFO: jump from "tinyidiot" to "damonarch" at 960,600
[2026-08-15T11:30:20.544] INFO: entering screen
[2026-08-15T11:30:21.589] NOTE: accepted client connection
[2026-08-15T11:30:21.589] INFO: saying hello as Synergy, protocol v1.8

Client:

INFO: entering screen
ERROR: invalid message from server: 
INFO: leaving screen
WARNING: failed to connect to server: invalid message from server
NOTE: connecting to 'damonarch': invalid message from server
NOTE: connected to server

Additional information

I've tried using other versions of Synergy on the client-side (all the same, even synergy-vintage); not sure what to try server-side.

The issue does not reproduce on a Deskflow client on Windows 10 (also in Synergy compatibility mode)