[server terminates connection] Upgrading from 2.x to 3.x SSL read errors after connect about freerdp

[akallabeth]

@dolfinus

1. can you retest with xfreerdp or sdl-freerdp?
2. can you post your buildconfig?
3. did you update remmina as well? (I don´t think the old version can handle FreeRDP3)

I suspect a remmina bug with new freerdp3 as there have been many changes and some might have been missed. (did just successfully connect to our test domain with xfreerdp)

[dolfinus]

can you retest with xfreerdp

Yes, just the same issue.

freerdp2_nla.txt - working as expected.
freerdp3_nla.txt - black screen.

can you post your buildconfig?

This is FreeRDP version 2.11.4 (2.11.4)
Build configuration: BUILD_TESTING=OFF BUILTIN_CHANNELS=ON HAVE_AIO_H=1 HAVE_EXECINFO_BACKTRACE=1 HAVE_EXECINFO_BACKTRACE_SYMBOLS=1 HAVE_EXECINFO_BACKTRACE_SYMBOLS_FD=1 HAVE_EXECINFO_H=ON HAVE_EXECINFO_HEADER=1 HAVE_FCNTL_H=1 HAVE_GETLOGIN_R=1 HAVE_GETPWUID_R=1 HAVE_INTTYPES_H=1 HAVE_JOURNALD_H=TRUE HAVE_MATH_C99_LONG_DOUBLE=1 HAVE_PIXMAN_REGION=OFF HAVE_POLL_H=1 HAVE_PTHREAD_MUTEX_TIMEDLOCK=ON HAVE_PTHREAD_MUTEX_TIMEDLOCK_LIBS= HAVE_PTHREAD_MUTEX_TIMEDLOCK_SYMBOL=1 HAVE_SYSLOG_H=1 HAVE_SYS_EVENTFD_H=1 HAVE_SYS_FILIO_H= HAVE_SYS_MODEM_H= HAVE_SYS_SELECT_H=1 HAVE_SYS_SOCKIO_H= HAVE_SYS_STRTIO_H= HAVE_SYS_TIMERFD_H=1 HAVE_TM_GMTOFF=1 HAVE_UNISTD_H=1 HAVE_XI_TOUCH_CLASS=1 WITH_ALSA=ON WITH_CAIRO=OFF WITH_CCACHE=ON WITH_CHANNELS=ON WITH_CLANG_FORMAT=ON WITH_CLIENT=ON WITH_CLIENT_AVAILABLE=1 WITH_CLIENT_CHANNELS=ON WITH_CLIENT_CHANNELS_AVAILABLE=1 WITH_CLIENT_COMMON=ON WITH_CLIENT_INTERFACE=OFF WITH_CUPS=ON WITH_DEBUG_ALL=OFF WITH_DEBUG_CAPABILITIES=OFF WITH_DEBUG_CERTIFICATE=OFF WITH_DEBUG_CHANNELS=OFF WITH_DEBUG_CLIPRDR=OFF WITH_DEBUG_DVC=OFF WITH_DEBUG_KBD=OFF WITH_DEBUG_LICENSE=OFF WITH_DEBUG_MUTEX=OFF WITH_DEBUG_NEGO=OFF WITH_DEBUG_NLA=OFF WITH_DEBUG_NTLM=OFF WITH_DEBUG_RAIL=OFF WITH_DEBUG_RDP=OFF WITH_DEBUG_RDPDR=OFF WITH_DEBUG_RDPEI=OFF WITH_DEBUG_RDPGFX=OFF WITH_DEBUG_REDIR=OFF WITH_DEBUG_RFX=OFF WITH_DEBUG_RINGBUFFER=OFF WITH_DEBUG_SCARD=OFF WITH_DEBUG_SND=OFF WITH_DEBUG_SVC=OFF WITH_DEBUG_SYMBOLS=OFF WITH_DEBUG_THREADS=OFF WITH_DEBUG_TIMEZONE=OFF WITH_DEBUG_TRANSPORT=OFF WITH_DEBUG_TSG=OFF WITH_DEBUG_TSMF=OFF WITH_DEBUG_TSMF=OFF WITH_DEBUG_TSMF_AVAILABLE=0 WITH_DEBUG_URBDRC=OFF WITH_DEBUG_WND=OFF WITH_DEBUG_X11=OFF WITH_DEBUG_X11_CLIPRDR=OFF WITH_DEBUG_X11_LOCAL_MOVESIZE=OFF WITH_DEBUG_XV=OFF WITH_DSP_EXPERIMENTAL=OFF WITH_DSP_FFMPEG=ON WITH_EVENTFD_READ_WRITE=1 WITH_FAAC=OFF WITH_FAAD2=OFF WITH_FFMPEG=TRUE WITH_FFMPEG=TRUE WITH_GFX_H264=ON WITH_GPROF=OFF WITH_GSM=OFF WITH_GSSAPI=OFF WITH_ICU=ON WITH_INTERNAL_MD4=OFF WITH_INTERNAL_MD5=OFF WITH_IPP=OFF WITH_JPEG=ON WITH_LAME=OFF WITH_LIBRARY_VERSIONING=ON WITH_LIBSYSTEMD=ON WITH_MACAUDIO=OFF WITH_MACAUDIO=OFF WITH_MACAUDIO_AVAILABLE=0 WITH_MANPAGES=ON WITH_MBEDTLS=OFF WITH_OPENCL=OFF WITH_OPENH264=OFF WITH_OPENSLES=OFF WITH_OPENSSL=ON WITH_OSS=ON WITH_PAM=ON WITH_PCSC=ON WITH_PROFILER=OFF WITH_PROXY=ON WITH_PROXY_MODULES=OFF WITH_PULSE=ON WITH_SAMPLE=OFF WITH_SANITIZE_ADDRESS=OFF WITH_SANITIZE_ADDRESS_AVAILABLE=1 WITH_SANITIZE_MEMORY=OFF WITH_SANITIZE_MEMORY_AVAILABLE=1 WITH_SANITIZE_THREAD=OFF WITH_SANITIZE_THREAD_AVAILABLE=1 WITH_SERVER=ON WITH_SERVER_CHANNELS=ON WITH_SERVER_INTERFACE=ON WITH_SHADOW=ON WITH_SMARTCARD_INSPECT=OFF WITH_SOXR=OFF WITH_SSE2=ON WITH_SWSCALE=ON WITH_THIRD_PARTY=OFF WITH_VAAPI=OFF WITH_VALGRIND_MEMCHECK=OFF WITH_VALGRIND_MEMCHECK_AVAILABLE=1 WITH_VERBOSE_WINPR_ASSERT=ON WITH_WAYLAND=ON WITH_WINPR_TOOLS=ON WITH_X11=ON WITH_XCURSOR=ON WITH_XDAMAGE=ON WITH_XEXT=ON WITH_XFIXES=ON WITH_XI=ON WITH_XINERAMA=ON WITH_XKBFILE=ON WITH_XRANDR=ON WITH_XRENDER=ON WITH_XSHM=ON WITH_XTEST=ON WITH_XV=ON WITH_ZLIB=ON
Build type:          None
CFLAGS:              -march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong -fno-plt -fPIC -Wall -Wno-unused-result -Wno-unused-but-set-variable -Wno-deprecated-declarations -fvisibility=hidden -Wimplicit-function-declaration -Wredundant-decls -g -fno-omit-frame-pointer -DWINPR_DLL
Compiler:            GNU, 13.2.1
Target architecture: x64

This is FreeRDP version 3.4.0 (n/a)
Build configuration: BUILD_TESTING=OFF WINPR_HAVE_AIO_H=1 WINPR_HAVE_EXECINFO_BACKTRACE=1 WINPR_HAVE_EXECINFO_BACKTRACE_SYMBOLS=1 WINPR_HAVE_EXECINFO_BACKTRACE_SYMBOLS_FD=1 WINPR_HAVE_EXECINFO_HEADER=1 WINPR_HAVE_FCNTL_H=1 WINPR_HAVE_GETLOGIN_R=1 WINPR_HAVE_GETPWUID_R=1 WINPR_HAVE_INTTYPES_H=1 WINPR_HAVE_POLL_H=1 WINPR_HAVE_PTHREAD_MUTEX_TIMEDLOCK_LIB=1 WINPR_HAVE_PTHREAD_MUTEX_TIMEDLOCK_LIBS= WINPR_HAVE_PTHREAD_MUTEX_TIMEDLOCK_SYMBOL=1 WINPR_HAVE_STDBOOL_H=1 WINPR_HAVE_STDINT_H=1 WINPR_HAVE_STRNDUP=1 WINPR_HAVE_SYSLOG_H=1 WINPR_HAVE_SYS_EVENTFD_H=1 WINPR_HAVE_SYS_FILIO_H= WINPR_HAVE_SYS_SELECT_H=1 WINPR_HAVE_SYS_SOCKIO_H= WINPR_HAVE_SYS_TIMERFD_H=1 WINPR_HAVE_TM_GMTOFF=1 WINPR_HAVE_UNISTD_H=1 WINPR_HAVE_UNWIND_H=1 WITH_AAD=ON WITH_ABSOLUTE_PLUGIN_LOAD_PATHS=ON WITH_ADD_PLUGIN_TO_RPATH=OFF WITH_ALSA=ON WITH_BINARY_VERSIONING=ON WITH_CAIRO=OFF WITH_CCACHE=ON WITH_CHANNELS=ON WITH_CLANG_FORMAT=ON WITH_CLIENT=ON WITH_CLIENT_AVAILABLE=1 WITH_CLIENT_CHANNELS=ON WITH_CLIENT_CHANNELS_AVAILABLE=1 WITH_CLIENT_COMMON=ON WITH_CLIENT_INTERFACE=OFF WITH_CLIENT_SDL=ON WITH_CLIENT_SDL_AVAILABLE=1 WITH_CUPS=ON WITH_DEBUG_ALL=OFF WITH_DEBUG_CAPABILITIES=OFF WITH_DEBUG_CERTIFICATE=OFF WITH_DEBUG_CHANNELS=OFF WITH_DEBUG_CLIPRDR=OFF WITH_DEBUG_CODECS=OFF WITH_DEBUG_DVC=OFF WITH_DEBUG_EVENTS=OFF WITH_DEBUG_KBD=OFF WITH_DEBUG_LICENSE=OFF WITH_DEBUG_MUTEX=OFF WITH_DEBUG_NEGO=OFF WITH_DEBUG_NLA=OFF WITH_DEBUG_NTLM=OFF WITH_DEBUG_RAIL=OFF WITH_DEBUG_RDP=OFF WITH_DEBUG_RDPDR=OFF WITH_DEBUG_RDPEI=OFF WITH_DEBUG_RDPGFX=OFF WITH_DEBUG_REDIR=OFF WITH_DEBUG_RFX=OFF WITH_DEBUG_RINGBUFFER=OFF WITH_DEBUG_SCARD=OFF WITH_DEBUG_SCHANNEL=OFF WITH_DEBUG_SDL_EVENTS=OFF WITH_DEBUG_SDL_KBD_EVENTS=OFF WITH_DEBUG_SND=OFF WITH_DEBUG_SVC=OFF WITH_DEBUG_SYMBOLS=OFF WITH_DEBUG_THREADS=OFF WITH_DEBUG_TIMEZONE=OFF WITH_DEBUG_TRANSPORT=OFF WITH_DEBUG_TSG=OFF WITH_DEBUG_TSMF=OFF WITH_DEBUG_TSMF_AVAILABLE=0 WITH_DEBUG_URBDRC=OFF WITH_DEBUG_WND=OFF WITH_DEBUG_X11=OFF WITH_DEBUG_X11_LOCAL_MOVESIZE=OFF WITH_DEBUG_XV=OFF WITH_DSP_EXPERIMENTAL=OFF WITH_DSP_FFMPEG=ON WITH_DSP_FFMPEG_AVAILABLE=1 WITH_EVENTFD_READ_WRITE=1 WITH_FAAC=OFF WITH_FAAD2=OFF WITH_FFMPEG=ON WITH_FREERDP_DEPRECATED=OFF WITH_FREERDP_DEPRECATED_COMMANDLINE=OFF WITH_FUSE=ON WITH_GFX_H264=ON WITH_GPROF=OFF WITH_GSM=OFF WITH_ICU=ON WITH_INTERNAL_MD4=OFF WITH_INTERNAL_MD5=OFF WITH_INTERNAL_RC4=OFF WITH_IPP=OFF WITH_JPEG=ON WITH_KRB5=ON WITH_KRB5_NO_NTLM_FALLBACK=OFF WITH_LAME=OFF WITH_LIBRARY_VERSIONING=ON WITH_LIBRESSL=OFF WITH_LODEPNG=OFF WITH_MACAUDIO=OFF WITH_MACAUDIO_AVAILABLE=0 WITH_MANPAGES=ON WITH_MBEDTLS=OFF WITH_NATIVE_SSPI=OFF WITH_NEON=OFF WITH_OPENCL=OFF WITH_OPENH264=OFF WITH_OPENSC_PKCS11_LINKED=OFF WITH_OPENSSL=ON WITH_OPUS=OFF WITH_OSS=ON WITH_PCSC=ON WITH_PKCS11=ON WITH_PLATFORM_SERVER=ON WITH_POLL=ON WITH_PROFILER=OFF WITH_PROXY=ON WITH_PROXY_APP=ON WITH_PROXY_EMULATE_SMARTCARD=OFF WITH_PROXY_MODULES=ON WITH_PULSE=ON WITH_RDTK=ON WITH_SAMPLE=ON WITH_SANITIZE_ADDRESS=OFF WITH_SANITIZE_ADDRESS_AVAILABLE=1 WITH_SANITIZE_MEMORY=OFF WITH_SANITIZE_MEMORY_AVAILABLE=1 WITH_SANITIZE_THREAD=OFF WITH_SANITIZE_THREAD_AVAILABLE=1 WITH_SDL_IMAGE_DIALOGS=OFF WITH_SDL_LINK_SHARED=ON WITH_SERVER=ON WITH_SERVER_CHANNELS=ON WITH_SERVER_INTERFACE=ON WITH_SHADOW=ON WITH_SMARTCARD_EMULATE=ON WITH_SMARTCARD_INSPECT=OFF WITH_SMARTCARD_PCSC=ON WITH_SOXR=OFF WITH_SSE2=OFF WITH_SWSCALE=ON WITH_SYSTEMD=ON WITH_THIRD_PARTY=OFF WITH_UNICODE_BUILTIN=OFF WITH_URIPARSER=OFF WITH_VAAPI=OFF WITH_VAAPI_AVAILABLE=1 WITH_VALGRIND_MEMCHECK=OFF WITH_VALGRIND_MEMCHECK_AVAILABLE=1 WITH_VERBOSE_WINPR_ASSERT=ON WITH_VIDEO_FFMPEG=ON WITH_VIDEO_FFMPEG_AVAILABLE=1 WITH_WAYLAND=ON WITH_WEBVIEW=ON WITH_WEBVIEW_QT=OFF WITH_WINPR_DEPRECATED=OFF WITH_WINPR_TOOLS=ON WITH_WIN_CONSOLE=ON WITH_X11=ON WITH_XCURSOR=ON WITH_XEXT=ON WITH_XFIXES=ON WITH_XI=ON WITH_XINERAMA=ON WITH_XRANDR=ON WITH_XRENDER=ON WITH_XV=ON
Build type:          None
CFLAGS:              -march=x86-64 -mtune=generic -O2 -pipe -fno-plt -fexceptions         -Wp,-D_FORTIFY_SOURCE=2 -Wformat -Werror=format-security         -fstack-clash-protection -fcf-protection -g -ffile-prefix-map=/build/freerdp/src=/usr/src/debug/freerdp -flto=auto -Wall -Wpedantic -Wno-padded -Wno-cast-align -Wno-declaration-after-statement -fPIC -Wall -fvisibility=hidden -Wimplicit-function-declaration -Wredundant-decls -g -fno-omit-frame-pointer
Compiler:            GNU, 13.2.1
Target architecture: x64

did you update remmina as well?

Yes, Remmina was build with -DWITH_FREERDP3=ON for freerdp3 and with -DWITH_FREERDP3=OFF for freerdp2. Otherwise it shows an error that RDP plugin not found.

[hardening]

Hum that's so strange, the connection seems to work perfectly and then we have that read retries exceeded on transport...

[akallabeth]

@dolfinus which openssl are you linking against?
from the logs:

1. the authentication succeeds
2. later the TLS read bails out with a failure
3. reconnect is activated and the loop repeats

[dolfinus]

$ openssl version
OpenSSL 3.2.1 30 Jan 2024

[akallabeth]

@dolfinus and your command line? (might help understanding what is going on here, this is very strange)

[dolfinus]

xfreerdp /v:host:port /cert:ignore /sec:nla /d:myrealm /u:username

RDP server uses self-signed certificate

[akallabeth]

@dolfinus ok, then where is the auto-reconnect in the logs from?

[dolfinus]

where is the auto-reconnect in the logs from?

I don't understand the question. I've changed log level to TRACING and redirected all the outputs to a file. That's it.

[akallabeth]

log entries like these are not possible with your command line:

[18:03:43:407] [133216:00020861] [DEBUG][com.freerdp.core.transport] - [transport_check_fds]: transport_check_fds: transport_read_pdu() - -1
[18:03:43:407] [133216:00020861] [DEBUG][com.freerdp.core.rdp] - [rdp_check_fds][0x58c9db0a03e0]: transport_check_fds() - -1
[18:03:43:407] [133216:00020861] [DEBUG][com.freerdp.core] - [freerdp_check_fds]: rdp_check_fds() - -1
[18:03:43:407] [133216:00020861] [INFO][com.freerdp.client.common] - [client_auto_reconnect_ex]: Network disconnect!
[18:03:43:407] [133216:00020861] [INFO][com.freerdp.client.common] - [client_auto_reconnect_ex]: Attempting reconnect (1 of 20)
[18:03:43:407] [133216:00020861] [INFO][com.freerdp.client.common] - [client_common_retry_dialog]: [connection] retry 1/20, delaying 15000ms before next attempt

[dolfinus]

Why do you think so?

[akallabeth]

because of the settings required to reach that code?
FreeRDP_AutoReconnectionEnabled = TRUE but default is FALSE except when /auto-reconnect is added on command line?

[dolfinus]

My freerdp package was installed using Arch Linux package manager, I haven't built it myself. But I don't see anything like that in a build configuration.

I didn't pass /auto-reconnect option to xfreerdp either. More than that, if I pass -auto-reconnect to disable this, I still see Attempting reconnect (1 of 20) in logs

[akallabeth]

@dolfinus ok, did find the reason for that, need to check if that is actually what should happen.

FreeRDP/libfreerdp/core/capabilities.c

Line 226 in 1f3a49c

settings->AutoReconnectionEnabled = (extraFlags & AUTORECONNECT_SUPPORTED) ? TRUE : FALSE;

followed by

FreeRDP/libfreerdp/core/capabilities.c

Line 171 in 1f3a49c

settings->AutoReconnectionEnabled = src->AutoReconnectionEnabled;

can activate it too.

anyway, the main thing is I can´t find anything in the logs that details why the connection breaks up.

can you do a git bisect between current master branch and stable-2.0 branch?
you don´t need to package, just:

git clone https://github.com/freerdp/freerdp
cd freerdp
git bisect start
git bisect bad
git checkout stable-2.0
git bisect good
cmake -GNinja -Bbuild-freerdp -S. -DCMAKE_INSTALL_PREFIX=/tmp/freerdp

then for each commit in the bisect:

cmake --build build-freerdp --target install && /tmp/freerdp/bin/xfreerdp <your args>

and depending on if it works/does not work/does not compile
git bisect good, git bisect bad or git bisect skip until you have the first broken commit?

NOTE: you might need to install build dependencies.

[dolfinus]

Tracked down to 7cef0cb

[akallabeth]

@dolfinus does not look like the commit is correct, no changes to transport or similar.

[dolfinus]

b5e8b419b is fine:
/tmp/freerdp/bin/xfreerdp /v:hostname /cert:ignore /sec:nla /d:admsk /u:msmarty5 /log-level:TRACE 2>&1 > b5e8b419b.log
b5e8b419b.log

[12:32:24:416] [175655:175656] [DEBUG][com.freerdp.core.rdp] - recv Monitor Layout Data PDU (0x37), length: 42
[12:32:24:516] [175655:175656] [DEBUG][com.freerdp.core.rdp] - recv Synchronize Data PDU (0x1F), length: 22
[12:32:24:516] [175655:175656] [DEBUG][com.freerdp.core.rdp] - [CONNECTION_STATE_FINALIZATION] received flag FINALIZE_SC_SYNCHRONIZE_PDU| [0x0001]
[12:32:24:516] [175655:175656] [DEBUG][com.freerdp.core.rdp] - recv Control Data PDU (0x14), length: 26
[12:32:24:516] [175655:175656] [DEBUG][com.freerdp.core.rdp] - [CONNECTION_STATE_FINALIZATION] received flag FINALIZE_SC_CONTROL_COOPERATE_PDU| [0x0002]
[12:32:24:516] [175655:175656] [DEBUG][com.freerdp.core.rdp] - recv Control Data PDU (0x14), length: 26
[12:32:24:516] [175655:175656] [DEBUG][com.freerdp.core.rdp] - [CONNECTION_STATE_FINALIZATION] received flag FINALIZE_SC_CONTROL_GRANTED_PDU| [0x0004]
[12:32:24:516] [175655:175656] [DEBUG][com.freerdp.core.rdp] - recv Font Map Data PDU (0x28), length: 26
[12:32:24:516] [175655:175656] [DEBUG][com.freerdp.core.rdp] - [CONNECTION_STATE_FINALIZATION] received flag FINALIZE_SC_FONT_MAP_PDU| [0x0008]
[12:32:24:516] [175655:175656] [DEBUG][com.freerdp.core.connection] - rdp_client_transition_to_state CONNECTION_STATE_FINALIZATION --> CONNECTION_STATE_ACTIVE

7cef0cb8d is failing:
/tmp/freerdp/bin/xfreerdp /v:hostname /cert:ignore /sec:nla /d:admsk /u:msmarty5 /log-level:TRACE 2>&1 > 7cef0cb8d.log
7cef0cb8d.log

[12:34:10:392] [179155:179156] [DEBUG][com.freerdp.core.rdp] - recv Monitor Layout Data PDU (0x37), length: 42
[12:34:10:493] [179155:179156] [DEBUG][com.freerdp.core.transport] - transport_check_fds: transport_read_pdu() - -1
[12:34:10:493] [179155:179156] [DEBUG][com.freerdp.core.rdp] - transport_check_fds() - -1
[12:34:10:494] [179155:179156] [DEBUG][com.freerdp.core.rdp] - [CONNECTION_STATE_FINALIZATION] reset finalize_sc_pdus
[12:34:10:494] [179155:179156] [DEBUG][com.freerdp.core.connection] - rdp_client_transition_to_state CONNECTION_STATE_FINALIZATION --> CONNECTION_STATE_INITIAL

[dolfinus]

I cannot compile commits from 2021 and 2022 because they are not compatible with modern OpenSSL and FFmpeg 6. So there can be a commit with kerberos/auth issue, but I cannot even build it.

But transport_read_pdu() - -1 appears in logs of latest commit in master branch, just before Network disconnect! message:

/tmp/freerdp/bin/xfreerdp /v:hostname /cert:ignore /sec:nla /d:admsk /u:msmarty5 /log-level:TRACE 2>&1 > master.log
master.log

[12:58:39:611] [195060:0002f9f5] [DEBUG][com.freerdp.core.transport] - [transport_check_fds]: transport_check_fds: transport_read_pdu() - -1
[12:58:39:611] [195060:0002f9f5] [DEBUG][com.freerdp.core.rdp] - [rdp_check_fds][0x55d6d3ba23e0]: transport_check_fds() - -1
[12:58:39:611] [195060:0002f9f5] [DEBUG][com.freerdp.core] - [freerdp_check_fds]: rdp_check_fds() - -1
[12:58:39:611] [195060:0002f9f5] [INFO][com.freerdp.client.common] - [client_auto_reconnect_ex]: Network disconnect!
[12:58:39:613] [195060:0002f9f5] [DEBUG][com.freerdp.core.rdp] - [rdp_finalize_reset_flags][0x55d6d3ba23e0]: [CONNECTION_STATE_FINALIZATION_CLIENT_SYNC] reset finalize_sc_pdus
[12:58:39:613] [195060:0002f9f5] [DEBUG][com.freerdp.core.rdp] - [rdp_client_transition_to_state][0x55d6d3ba23e0]: CONNECTION_STATE_FINALIZATION_CLIENT_SYNC --> CONNECTION_STATE_INITIAL

So this may be related.

[akallabeth]

@dolfinus to me this looks like the remote end has a bug.

• can you get log files from the remote why it terminates connection?
• can you identify which change in that commit exactly triggered the problem?

we did fix a lot of protocol violations and that might be one of these cases. (might be wrong, but I got a strong suspicion)
the commit you reference fixes the capability settings to the ones agreed upon by client and server (previously they were not always consistent)

[dolfinus]

I have no access to remote server logs, I'm not an administrator.

[akallabeth]

do you know, by chance, which software is running there? might be able to check if that is known. (doubt it is a direct connection to Windows Server 2016 Standard)

[akallabeth]

as for where there might be the reason:
in capabilities.c we added a few checks. (just ignore new settings, just the changed read functions now split into read and apply you can revert one by one and check where it breaks)

[dolfinus]

I've build xfreerdp with WITH_DEBUG_CAPABILITIES=1:

cmake -GNinja -Bbuild-freerdp -S. --fresh -DCMAKE_INSTALL_PREFIX=/tmp/freerdp -DWITH_DEBUG_CAPABILITIES=1

Here are logs:
b5e8b419b.log
7cef0cb8d.log
master.log

The difference is here:
b5e8b419b

Sending 
GeneralCapabilitySet (length 20):
	osMajorType: 0x0001
	osMinorType: 0x0003
	protocolVersion: 0x0200

vs. 7cef0cb8d:

Sending 
GeneralCapabilitySet (length 20):
	osMajorType: 0x0004
	osMinorType: 0x0007
	protocolVersion: 0x0000

This is caused by:
7cef0cb8d#diff-23782638b8d86b1e888e5cc37a2b4789ddc107c5321803ab4bce2b99563c7aebL253

If I patch master:

diff --git a/libfreerdp/core/capabilities.c b/libfreerdp/core/capabilities.c
index f59b956a8..0762e30d7 100644
--- a/libfreerdp/core/capabilities.c
+++ b/libfreerdp/core/capabilities.c
@@ -166,6 +166,7 @@ static BOOL rdp_apply_general_capability_set(rdpSettings* settings, const rdpSet
                settings->OsMinorType = src->OsMinorType;
        }
 
+       settings->CapsProtocolVersion = src->CapsProtocolVersion;
        settings->NoBitmapCompressionHeader = src->NoBitmapCompressionHeader;
        settings->LongCredentialsSupported = src->LongCredentialsSupported;
        settings->AutoReconnectionPacketSupported = src->AutoReconnectionPacketSupported;

then RDP is working properly:
master_patched.log

This solves #10060 as well.

[dolfinus]

Created #10130

[akallabeth]

@dolfinus nice catch, great work! thank you!