before I could select all pictures and use noise reduction on all pictures which I selected, but now it doesn't work and I need to add it one by one but that takes so long. I don't have time for that.

Before I could select all pictures and use noise reduction on all pictures together which I selected, but now it doesn't work and I need to add it one by one but that takes so long. I don't have time for that. Please I want to use noise reduction on all selected pictures again. Who can help me? Thanks in advance! 

P.s. when you have a solution in Dutch, I prefer that :-)