SUMMARY After a recent update, when connecting using mstsc or krdc, the RDP client shows no prompts—only a black screen appears before immediately disconnecting. Currently, it can only be confirmed that krdp has issues starting from version 6.5.0 on Neon. Older Neon versions are no longer available, so this cannot be verified. Connecting with other remote clients such as krfb works fine. STEPS TO REPRODUCE 1. Start krdpserver 2. Connect to krdp using krdc/mstsc 3. The RDP client will prompt about an abnormal certificate—ignore it OBSERVED RESULT A black screen is displayed, then the connection is immediately disconnected EXPECTED RESULT Use the krdp function normally SOFTWARE/OS VERSIONS Operating System: KDE neon User Edition KDE Plasma Version: 6.5.2 KDE Frameworks Version: 6.19.0 Qt Version: 6.9.3 Kernel Version: 6.14.0-36-generic (64-bit) Graphics Platform: Wayland Processors: 6 × Intel® Core™ i5-8500 CPU @ 3.00GHz Memory: 32 GiB of RAM (31.0 GiB usable) Graphics Processor: Intel® UHD Graphics 630 Manufacturer: Dell Inc. Product Name: ChengMing 3980 ADDITIONAL INFORMATION mstsc login logs: 2025/11/21 21:47 krdpserver org.kde.krdp: Session setup completed, start processing... 2025/11/21 21:47 krdpserver [21:47:19:225] [2925:00001006] [ERROR][com.freerdp.core.transport] - [transport_read_layer]: BIO_read returned a system error 104: 连接被对方重置 2025/11/21 21:47 krdpserver [21:47:19:225] [2925:00001006] [ERROR][com.freerdp.core.peer] - [transport_read_layer]: ERRCONNECT_CONNECT_TRANSPORT_FAILED [0x0002000D] 2025/11/21 21:47 krdpserver org.kde.krdp: Unable to check file descriptor 2025/11/21 21:47 krdpserver org.kde.krdp: Closing session 2025/11/21 21:47 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 21:47 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 21:47 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 21:47 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 21:47 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 21:47 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 21:47 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 21:47 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 21:47 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "" interface "org.freedesktop.portal.Session" member "Close": Object path cannot be empty 2025/11/21 21:47 krdpserver org.kde.krdp: Closing Freedesktop Portal Session 2025/11/21 21:47 krdpserver org.kde.krdp: Session setup completed, start processing... 2025/11/21 21:47 krdpserver org.kde.krdp: New client connected: Windows platform Windows NT 2025/11/21 21:47 krdpserver org.kde.krdp: Unable to check file descriptor 2025/11/21 21:47 krdpserver [21:47:24:896] [2925:00001007] [ERROR][com.freerdp.core.peer] - [rdp_peer_handle_state_active]: PostConnect for peer 0x5dd244b4dbc0 failed 2025/11/21 21:47 krdpserver [21:47:24:896] [2925:00001007] [ERROR][com.freerdp.core.transport] - [transport_check_fds]: transport_check_fds: transport->ReceiveCallback() - STATE_RUN_FAILED [-1] 2025/11/21 21:47 krdpserver org.kde.krdp: Closing session 2025/11/21 21:47 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 21:47 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 21:47 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 21:47 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 21:47 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 21:47 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 21:47 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 21:47 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 21:47 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "" interface "org.freedesktop.portal.Session" member "Close": Object path cannot be empty 2025/11/21 21:47 krdpserver org.kde.krdp: Closing Freedesktop Portal Session kdrc login logs: 2025/11/21 22:06 krdpserver org.kde.krdp: Session setup completed, start processing... 2025/11/21 22:06 krdpserver [22:06:50:834] [2925:00001348] [ERROR][com.freerdp.core.peer] - [rdp_peer_handle_state_active]: PostConnect for peer 0x5dd244316700 failed 2025/11/21 22:06 krdpserver [22:06:50:834] [2925:00001348] [ERROR][com.freerdp.core.transport] - [transport_check_fds]: transport_check_fds: transport->ReceiveCallback() - STATE_RUN_FAILED [-1] 2025/11/21 22:06 krdpserver org.kde.krdp: New client connected: Unspecified platform Unspecified version 2025/11/21 22:06 krdpserver org.kde.krdp: Unable to check file descriptor 2025/11/21 22:06 krdpserver org.kde.krdp: Closing session 2025/11/21 22:06 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 22:06 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 22:06 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 22:06 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 22:06 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 22:06 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 22:06 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 22:06 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "/org/freedesktop/portal/desktop" interface "org.freedesktop.portal.RemoteDesktop" member "NotifyKeyboardKeycode": Marshalling failed: Invalid object path passed in arguments 2025/11/21 22:06 krdpserver qt.dbus.integration: QDBusConnection: error: could not send message to service "org.freedesktop.portal.Desktop" path "" interface "org.freedesktop.portal.Session" member "Close": Object path cannot be empty 2025/11/21 22:06 krdpserver org.kde.krdp: Closing Freedesktop Portal Session
Update: After testing, both the krdp configured in the settings and the krdpserver command can be connected via KRDC, but still cannot be connected via mstsc.
I've also noticed some changes for KRDP after updating to Plasma 6.5.x in KDE neon. One thing I've noticed is that starting from 6.5.0 you need to check "Allow me to save credentials" in the MS Win11 client to successfully connect to Plasma RDP. Without this checkbox enabled I don't even get the user and password prompt (it was definitely not the case in Plasma 6.4.x). You can still input the password and uncheck "Remember me" in the dialog to avoid saving the credentials. Even with this workaround enabled, it usually takes at least 2 attempts to connect to the Plasma desktop (first attempt usually ends with error in the client), but sometimes I need more attempts or relaunch the client etc. It is a kind of roulette to get to my remote Plasma desktop, but once it successfully connects, it usualy works fine.
(In reply to KOPRajs from comment #2) I tried your method, and it does work. Now I at least have a workaround to perform RDP login, rather than using the traditional VNC protocol. Thank you very much!