Data corruption/re-write. Installed a bunch of psychedelic programs I bought on the black market and restructured my OS from the kernel level. Worth it because shutdown/sleep signals were being ignored as well as CPU buffer trashing issues (resulting in system crashes, hangups, etc.). Works a lot better now, but handshakes are difficult because my non-conforming configuration isn't recognized by the majority of the network. Still very much worth it though as I find complete network access isn't exactly necessary.
my non-conforming configuration isn't recognized by the majority of the network
This could be a case of nodes running outdated software, the current standard protocols can handle any unknown configuration just fine. These are a source of a lot of holes and vulnerabilities that can pose a serious risk, they should be updated as soon as possible. If you have to keep outdated systems in your network e.g. running on legacy hardware, or make the ocasional connection, you'll have to monitor them and isolate them from your critical infrastructure, at least with a good firewall and a strict configuration when possible.