When activating agents in AWS, you encounter error with Event ID 705 that has the following description:
Unable to activate the Agent/Appliance. This maybe caused by the system clock on the computer being out of sync with the Manager system clock.
Sometimes, you also get General Certificate rejection error. The issue only occurs in Windows 2012 R2 platform.
The issue occurs because you have set your environment to follow Windows 2008 R2 template and set the Maximum Transmission Unit (MTU) to 9001 Bytes causing network problems. Based on Amazon's KB article on VCP Peering Limitations, the supported maximum MTU across a VCP peering connection is only 1500 Bytes. Hence, high configured MTU causes activation failure.
To resolve the issue, change the MTU size based on AWS requirement to make sure the set up can work properly when VPC is involved.