What is this molten metal coming from the engine of an Avro RJ 100?
I do not see anything in your photo, apart the engine that looks perfectly normal. 

Anyway
here it is written that the fuel burns at up to 2000 degrees Celsius and the temperature at which metals in this part of the engine start to melt is 1300 degrees Celsius. Hence the metal may melt if something goes wrong.

Avro RJ100 has four engines so should be able to land with one inoperative. From the question I have just asked myself, it will not be qualified as accident so may not get widely known.