我正在尝试在我的 Ubuntu 20.04 上使用 Remmina 到 Windows 10 服务器的 RDP，但它一直失败，并显示“无法连接到”“RDP 服务器”。我已经在网上寻找答案已经尝试了所有这些方法，但它仍然不起作用：
- 删除 ~/.freerdp/known_host: 我找不到这样的文件甚至目录。我唯一类似的目录是 ~/.config/freerdp ，当我查看该文件夹时，没有这样的 known_host 文件。
- 转到高级选项卡并将安全协议协商更改为 TSL/RDP/...：我已经尝试了所有选项，但都不起作用
此外，我确信服务器可以正常工作，因为我能够使用我朋友的笔记本电脑和 Ubuntu 16.04 Remmina 和我的笔记本电脑的 Windows 10 远程桌面（双启动）进行 RDP。因此我不知道这里有什么问题。我在想我在 Ubuntu 上的网络设置有问题，但不确定要检查什么。
有人可以建议我下一步该怎么做吗？非常感谢！
Remmina 版本：1.4.7，freerdp 版本：2.2.0
下面是调试日志
** (org.remmina.Remmina:11009): DEBUG: 21:19:51.180: [precommand] (null)
** (org.remmina.Remmina:11009): DEBUG: 21:19:51.181: [precommand] updated to:
** (org.remmina.Remmina:11009): DEBUG: 21:19:51.182: (remmina_rdp_main) - Not using system proxy settings
** (org.remmina.Remmina:11009): DEBUG: 21:19:51.182: (remmina_rdp_tunnel_init) - Tunnel init
** (org.remmina.Remmina:11009): DEBUG: 21:19:51.182: SSH tunnel initialization…
** (org.remmina.Remmina:11009): DEBUG: 21:19:51.183: server: 172.**.***.**, port: 3389
** (org.remmina.Remmina:11009): DEBUG: 21:19:51.183: (remmina_rdp_tunnel_init) - protocol_plugin_start_direct_tunnel() returned [172.**.***.**]:3389
** (org.remmina.Remmina:11009): DEBUG: 21:19:51.183: (remmina_rdp_tunnel_init) - Tunnel has been optionally initialized. Now connecting to 172.**.***.**:3389
** (org.remmina.Remmina:11009): DEBUG: 21:19:51.183: (remmina_rdp_main) - proxy_type: (null)
** (org.remmina.Remmina:11009): DEBUG: 21:19:51.183: (remmina_rdp_main) - proxy_username: (null)
** (org.remmina.Remmina:11009): DEBUG: 21:19:51.183: (remmina_rdp_main) - proxy_password: (null)
** (org.remmina.Remmina:11009): DEBUG: 21:19:51.183: (remmina_rdp_main) - proxy_hostname: (null)
** (org.remmina.Remmina:11009): DEBUG: 21:19:51.183: (remmina_rdp_main) - proxy_port: 80
[21:19:51:125] [11009:11189] [INFO][com.freerdp.core] - freerdp_connect:freerdp_set_last_error_ex resetting error state
[21:19:51:125] [11009:11189] [INFO][com.freerdp.client.common.cmdline] - loading channelEx rdpdr
[21:19:51:125] [11009:11189] [INFO][com.freerdp.client.common.cmdline] - loading channelEx rdpsnd
[21:19:51:125] [11009:11189] [INFO][com.freerdp.client.common.cmdline] - loading channelEx cliprdr
[21:19:51:125] [11009:11189] [INFO][com.freerdp.client.common.cmdline] - loading channelEx drdynvc
[21:19:51:126] [11009:11189] [INFO][com.freerdp.core] - freerdp_tcp_is_hostname_resolvable:freerdp_set_last_error_ex resetting error state
[21:19:51:126] [11009:11189] [INFO][com.freerdp.core] - freerdp_tcp_connect:freerdp_set_last_error_ex resetting error state
[21:19:54:179] [11009:11189] [ERROR][com.freerdp.core.transport] - BIO_should_retry returned a system error 32: Broken pipe
[21:19:54:179] [11009:11189] [ERROR][com.freerdp.core] - transport_write:freerdp_set_last_error_ex ERRCONNECT_CONNECT_TRANSPORT_FAILED [0x0002000D]
[21:19:54:184] [11009:11189] [INFO][com.freerdp.core] - freerdp_tcp_is_hostname_resolvable:freerdp_set_last_error_ex resetting error state
[21:19:54:184] [11009:11189] [INFO][com.freerdp.core] - freerdp_tcp_connect:freerdp_set_last_error_ex resetting error state
[21:19:57:251] [11009:11189] [ERROR][com.freerdp.core.transport] - BIO_should_retry returned a system error 32: Broken pipe
[21:19:57:251] [11009:11189] [ERROR][com.freerdp.core] - transport_write:freerdp_set_last_error_ex ERRCONNECT_CONNECT_TRANSPORT_FAILED [0x0002000D]
[21:19:57:251] [11009:11189] [ERROR][com.freerdp.core] - freerdp_post_connect failed
libfreerdp returned code is 0002000D
** (org.remmina.Remmina:11009): DEBUG: 21:19:57.313: [postcommand] (null)
** (org.remmina.Remmina:11009): DEBUG: 21:19:57.313: [postcommand] updated to:
** (org.remmina.Remmina:11009): DEBUG: 21:19:57.313: (rco_on_disconnect) - Disconnect signal received on RemminaProtocolWidget
** (org.remmina.Remmina:11009): DEBUG: 21:19:57.316: (rco_on_disconnect) - Could not disconnect