Hi there and thanks for the post.
We've seen this happen at times if the "DSM Essentials Network Monitor" service stops unexpectedly. Sometimes, there can be a device in the discovery range that can cause this service to crash (which shouldn't happen). The next time you run into this, I'd look and see if any of the DSM services have stopped. And it would be good to know if there are any dump files in the OME bin directory. If that is the case, you should open a ticket at 800-945-3355 and have the dump file reviewed along with other log files.
Hope that helps.
Rob