When installed in some restricted Microsoft Windows environments, the SIEM Collector might intermittently show that it is connecting using Managed Extensibility Framework (MEF) version 4 instead of MEF version 6. When this happens, you also notice a delay as the SIEM Collector starts up. The cause of this issue is the computer attempting to resolve ctldl.windowsupdate.com, but being unable to. This might be caused by, for example, issues with external DNS resolution. For more information and a solution, see KB84483.