Neglected Muddy Steam Boiler Running Without Water

I arrive at a steam boiler maintenance. I go to check the site glass and noticed there’s no water in boiler and firing up. Therefore I got a bucket and attempt to see if any water will drain out. Nothing comes out of the drain. Therefore with boiler off for a little while I tap on the side of the drain. A little bit of mud starts to drip out. Next add water to the boiler with the drain opened. Nothing comes out of the drain it is completely plugged. Then I bang on the side of the low-water cut off where the drain is and some more muddy sludge starts to droop out of the boiler. I do this numerous times until I get the water to come out of the drain. I didn’t perform my maintenance on the steam boiler. Furthermore test operation of the steam boiler and all safeties.