Alta currently does not handle loading a class when the first reference to it is from an object passed through IPC. Currently, if any required classes are unavailable in the target typespace, the object is not passed. Similar to page-faults during IPC in a traditional kernel, handling such a fault in Alta would require the kernel to generate a class-fault exception to the parent process. This, in turn, would require a thread to have two outstanding IPC operations at one time, which, in turn, requires Alta to support idempotent IPC operations, which it does not at this time.