I am having the same problem described here Development Jar error however I need help adding the EJML-core-0.26 library (the one in my industrialcraft-2-2.2.815-experimental.jar file) I am using forkage but I saw the thread above so I thought that this error was related to IC2
Here is the Server-sided crash report (the one similar to the other thread
Here is the Client-sided crash report (if needed)