When using Remote Desktop to a Windows Server* 2008 based system after installing Symantec Endpoint Protection* your connection might drop after a short time with the following error displayed in a Windows* pop-up message:

Because of an error in data encryption, this session will end. Please try connecting to the remote computer again.

According to the Symantec* Support Knowledgebase, this issue is not caused by Symantec Endpoint Protection.

You can work around this issue by disabling Large Send Offload on the affected server.
Disable Large Send Offload (IPv4) and Large Send Offload (IPv6) on an Intel® Ethernet adapter in the advanced properties tab for the adapter in Windows Device Manager*.

Additional Information
Symantec Support Knowledgebase Article*
Advanced settings for Intel® 10/100 and Gigabit Adapters
Advanced driver settings for Intel® Ethernet 10 Gigabit Server Adapters
Advanced settings for Intel® PRO/10GbE Server Adapters

Operating System:

Windows Server 2008 *

This applies to:

IntelŽ 10 Gigabit AF DA Dual Port Server Adapter IntelŽ 10 Gigabit AT Server Adapter IntelŽ 10 Gigabit CX4 Dual Port Server Adapter IntelŽ 10 Gigabit XF LR Server Adapter IntelŽ 10 Gigabit XF SR Dual Port Server Adapter IntelŽ 10 Gigabit XF SR Server Adapter IntelŽ Ethernet Converged Network Adapter X520 Series IntelŽ Ethernet Converged Network Adapter X540-T1 IntelŽ Ethernet Converged Network Adapter X540-T2 IntelŽ Ethernet Server Adapter I210-T1 IntelŽ Ethernet Server Adapter I340-F4 IntelŽ Ethernet Server Adapter I340-T4 IntelŽ Ethernet Server Adapter I350-F2 IntelŽ Ethernet Server Adapter I350-F4 IntelŽ Ethernet Server Adapter I350-T2 IntelŽ Ethernet Server Adapter I350-T4 IntelŽ Ethernet Server Adapter X520 Series IntelŽ Ethernet Server Adapter X520-DA2 IntelŽ Ethernet Server Adapter X520-LR1 IntelŽ Ethernet Server Adapter X520-SR1 IntelŽ Ethernet Server Adapter X520-SR2 IntelŽ Ethernet Server Adapter X520-T2 IntelŽ Gigabit CT Desktop Adapter IntelŽ Gigabit EF Dual Port Server Adapter IntelŽ Gigabit ET Dual Port Server Adapter IntelŽ Gigabit ET Quad Port Server Adapter IntelŽ Gigabit ET2 Quad Port Server Adapter IntelŽ PRO/100 M Desktop Adapter IntelŽ PRO/100 S Desktop Adapter IntelŽ PRO/100 S Dual Port Server Adapter IntelŽ PRO/100 S Management Adapter IntelŽ PRO/100 S Server Adapter IntelŽ PRO/1000 GT Desktop Adapter IntelŽ PRO/1000 GT Quad Port Server Adapter IntelŽ PRO/1000 MF Dual Port Server Adapter IntelŽ PRO/1000 MF Server Adapter IntelŽ PRO/1000 MF Server Adapter (LX) IntelŽ PRO/1000 MT Desktop Adapter IntelŽ PRO/1000 MT Dual Port Server Adapter IntelŽ PRO/1000 MT Quad Port Server Adapter IntelŽ PRO/1000 MT Server Adapter IntelŽ PRO/1000 PF Dual Port Server Adapter IntelŽ PRO/1000 PF Quad Port Server Adapter IntelŽ PRO/1000 PF Server Adapter IntelŽ PRO/1000 PT Desktop Adapter IntelŽ PRO/1000 PT Dual Port Server Adapter IntelŽ PRO/1000 PT Quad Port Low Profile Server Adapter IntelŽ PRO/1000 PT Quad Port Server Adapter IntelŽ PRO/1000 PT Server Adapter IntelŽ PRO/1000 XF Server Adapter IntelŽ PRO/1000 XT Low Profile Server Adapter IntelŽ PRO/1000 XT Server Adapter IntelŽ PRO/10GbE CX4 Server Adapter IntelŽ PRO/10GbE LR Server Adapter IntelŽ PRO/10GbE SR Server Adapter NetEffect™ Ethernet Server Cluster Adapters