Instructions on inserting/removing your SIM can help with activation issues/errors and connectivity issues.
Ensure the device is powered off.
Press and hold the Power button (top right of the device) until "MiFi Powering Off" displays then release.
Press your finger against the battery door removal tab, then lift and remove the battery cover.
Insert your finger into the battery removal divot and lift the battery out of the battery compartment.
Locate the SIM card protector.
Lift to open the SIM card protector.
Push the SIM card toward the SIM card slot (gold contacts facing down with the notched edge in the lower-right). Carefully slide the card until it clicks into place.
An image showing the correct SIM orientation is embossed on the device near the SIM slot.