Measuring current on 25W incandescent lamp - loud bang/spark from DMM probes?
You forgot an ammeter is low resistance and shorted something out. Can't connect it to an unbroken circuit because that is parallel. Gotta break the circuit and connect in series. The ammeter would already be wired up before you turned things on if you did this. You would not turn thing on then touch the probes.
Replace the fuse in the DMM.