As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT NR 6266 - IAD-BTV - ABORTED THE TAKEOFF, DUE TO THE RIGHT BETA CAP LIGHT ILLUMINATING. AIRCRAFT RETURNED TO GATE WITH NO FURTHER INCIDENTS. MAINTENANCE REPLACED THE BETA SWITCH. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (M)