It appears that the Benchmark Editor cannot open elements that have a very large number of fields. For example, if the FDCC XP XCCDF file is opened as a benchmark (resulting in both the OVAL and the PATCHES files opening) and the "federal_desktop_core_configuration_version_1.1.1.0" Profile is double clicked, this causes a brief pause and then execution continues without opening a high-level editor. A OutOfMemoryError is thrown but does not kill the application. This does not happen if the XCCDF file is opened alone.
The application needs better memory control to avoid this behavior.