Either you didn't attach the hypersim to the SIM correctly or the hypersim is broken. The two errors (USIM-MEP / USIM Card Error) are displayed when a SIM card is inserted but not the "correct" one. Try re-attaching - very carefully - but first perform CPR on a standard phone, for just in case. The CPR will also tell you if your SIM card is OK.
The Sim card alone does work in my old T-Mobile Sidekick 4G. I cut a good amount of the top off, so that the HyperSim chip is still accessible, and I did sand paper the T-Mobile Sim.
Is the little tray piece required to be in place, because it still seems like such a tight fit, and I think I may have broke off a little piece of the "pully" to get it out. I haven't been using the tray piece, and I have been removing it delicately with tweezers. I'm going to try again tonight with the tray piece in place.