EMB ERJ 145 ER/LR
Flight Crew Air Transport Pilot (ATP)
Time Pressure; Training / Qualification
Aircraft Equipment Problem Less Severe
Flight Crew Rejected Takeoff; Flight Crew Returned To Gate; General Flight Cancelled / Delayed; General Maintenance Action
Environment - Non Weather Related; Aircraft
Everything [was] normal up to takeoff roll; after calling 80 KTS; [we had a] E1 THRUST REVERSE DISAGREE [EICAS]  (90 KTS) caution followed by Takeoff Configuration Warning alarm. I called the annunciation and the Captain called for the abort. I immediately let Tower know and told the passengers to remain seated. Once off the active; the Captain called for the aborted Takeoff Checklist completed. The Captain then called Maintenance while I explained the situation to the passengers and Flight Attendant. We worked with Operations/Dispatch for the gate return and Contract Maintenance took it from there. The largest threat was it being very early morning and an aborted takeoff was the last thing expected. All parties handled the situation according to company policy/checklists and the passengers were informed every step of the way.
It was dark. The runway was wet. It was very early in the morning.
An EMB-145 EICAS alerted E1 THRUST REVERSE DISAGREE at about 90 KTS during takeoff so the Captain rejected the takeoff; completed the checklist and returned to the gate for maintenance.