1994 BMW540i Break Light Out indicator reset

I would recommend that you check to make shore that you replaced the bulb with the right bulb. It is common for two different bulbs to have the same base but a different spec on the filament. For example an 1157 and a 2057 bulb are visually identical, but the filaments are different. The reason this difference matters is that the system that monitors the lighting on your car moniters the ohms of resistance in the circuit. A bulb with a lighter filament provides more Resistance and will trigger the system to alert you that a light is out.

If the brake light works, disconnect battery negative with ignition key ON and Radio ON, but engine OFF, four minutes after connect Battery terminal, do not panic if terminal sparks wile connecting, *** it well turn ignition key OFF, than start the motor and verify
if problem remains

I have the same problem when I changed my car rear light with LED new lights so you need to check as below

check to make shore that you replaced the bulb with the right bulb.
check brake light switch ,it is on top of brake pedal.
check brake fuse in the fuse box.