Symptom:
AnyConnect clients are able to connect, but get immediately disconnected. The following are seen in syslogs:

%ASA-6-725007 SSL session with remote_device interface_name : IP_address / port terminated.
%ASA-6-722023: Group group User user-name IP IP_address SVC connection terminated with compression
%ASA-6-716058: Group group User user IP ip AnyConnect session lost connection. Waiting to resume.
%ASA-5-722037: Group group User user-name IP IP_address SVC closing connection: Compression error. 
 %ASA-6-722027: Group group User user-name IP IP_address SVC decompression history reset
%ASA-6-716059: Group group User user IP ip AnyConnect session resumed. Connection from ip2 .
%ASA-3-722021: Group group User user-name IP IP_address Unable to start compression due to lack of memory resources

ASA can also crash  with traceback pointing to "ssl_compress_record" when low memory is observed.

Conditions:
Compression is configured for AnyConnect.