My Yamaha MX A5000 keeps going into protection mode. Why can that be happening and most importantly, how do i reset it

You must repair the amplifier first.
Take it to an authorised Yamaha service centre.

there may be a bad speaker or speaker connection and the yamaha is trying to protect itself.
there may be a shorted component inside the stereo allowing an improper voltage to go to the speakers and the yamaha is trying to protect your speakers.

check ur speaker wires, try disconnect all wires from back of unit and then try to turn on unit .if it stays on whit no wires attached than u have short connection at speaker wires . if doesn`t come on then try to fasten screws at back of the unit , may sound like BS but if amp board don`t have good ground connection it can go in protection mode
happened to me on RX-V592

check ur speaker wires, try disconnect all wires from back of unit and then try to turn on unit .
if it stays on whit no wires attached than u have short connection at speaker wires .
if doesn`t come on then try to fasten screws at back of the unit ,
may sound like BS but if amp board don`t have good ground connection it can go in protection mode happened to me on RX-V592

First check that the speaker wires are not shorting, if okay! the problem is in the audio output stage of the receiver, the protect mode comes on if a load is detected.

If there is no apparent cause for the protection mode activating (such as shorted speakers, burning smell, blown fuses, lighting strike or mains power surges), reset the protection as follows and see what happens.

Connect power cord to mains and wait 5 seconds or so. While holding down "info" and "tone control" buttons, press "main zone" power button briefly and release, but keep "info" and "tone control" buttons pressed for at least 3 more seconds. The unit should power up. Assuming the reason for the protection has passed or been fixed, the unit can now be turned off and then back on with the "main zone" power button to restore normal operation mode.
If the protector activates again, the fault is still present and the unit needs to be repaired, ideally by a Yamaha authorised repairer.
There are dangerous voltages present in high power amps and a lot of grunt in terms of stored energy - best left to trained technicians.

If there is no apparent cause for the protection mode activating (such as shorted speakers, burning smell, blown fuses, lighting strike or mains power surges), reset the protection as follows and see what happens.

Connect power cord to mains and wait 5 seconds or so. While holding down "info" and "tone control" buttons, press "main zone" power button briefly and release, but keep "info" and "tone control" buttons pressed for at least 3 more seconds. The unit should power up. Assuming the reason for the protection has passed or been fixed, the unit can now be turned off and then back on with the "main zone" power button to restore normal operation mode.
If the protector activates again, the fault is still present and the unit needs to be repaired, ideally by a Yamaha authorised repairer.
There are dangerous voltages present in high power amps and a lot of grunt in terms of stored energy - best left to trained technicians.

Is it going into protect mode???
If so, check your speaker connections. Make sure there are no loose copper wires hanging out, and that your splices are clean at both the receiver and the speaker.