Wurst (Any version) seems to conflict with one of SecurityCraft's (SC) latest updates, starting 1.10 and continuing with any further update.
It can be replicated under any circumstance, simply have Wurst with Sinytra Connector, Forgified Fabric API, Wurst and any version of SC starting 1.10 (Crash persists both with or without Connectors Extras if it is of any concern).
SC and Wurst will load with no issues without the other, meaning SC will load with Connector, Extras and Forgified without crashing, and same goes for Wurst.
Crash log to start things off: https://mclo.gs/I8IADBE