Likely cause of this issue is the JVM version of the Application Server.
The agent log is showing following JVM version.
[INFO] [IntroscopeAgent.GC Event] Java Version is '1.6.0_17'.
Release : 20.11
Component : APM Agents
Check the agent log and try to find the JVM version that agent is using.
[INFO] [IntroscopeAgent.Properties] java.runtime.name=Java(TM) SE Runtime Environment
[INFO] [IntroscopeAgent.Properties] java.runtime.version=1.6.0_17-b04
In this case, the WebLogic Server is using Java 1.6.
Please consult with Application Server Admin and confirm this.
Also, inquire with Application Server admin if they can upgrade the Java version that this WebLogic Server is using.
Once you upgrade the Java to 1.8, this issue should not occur anymore.
Another workaround is to use the cloud proxy.