If you attempt to connect to a Windows 7 workstation using the RDP protocol TLS security, you may encounter the following error information from Remmina:
Dec 30 21:25:00 hostname remmina.desktop[4836]: [21:25:00:443] [4836:5478] [ERROR][com.freerdp.core] – freerdp_set_last_error ERRCONNECT_CONNECT_TRANSPORT_FAILED [0x2000D]
Dec 30 21:25:00 hostname remmina.desktop[4836]: [21:25:00:443] [4836:5478] [ERROR][com.freerdp.core.transport] – BIO_read returned an error: error:14094438:SSL routines:ssl3_read_bytes:tlsv1 alert internal error
To resolve the issue, you may simply need to edit the connection in Remmina, head to the Advanced tab, and choose TLS for Security (by default, it is “Negotiate”). I don’t know why the security negotiation appears to be failing in my case, but that resolved the issue for me.
Engineering Walden 
Funny fact: without TLS I can connect to one of my computers, but not to this in particular.
Thanks,
Pablo
i ended up battling with it. in the end, i made sure that the user was enabled on the PC for remote desktop. then set the thin client to negotiate.