This plug in was very, very good until Firefox killed its usefulness to any file on the local hard drive, such as image files received or sent via email, those downloaded from a thumb drive, or those taken and saved on a local hard drive by the computer owner. Firefox in some sort of misguided, perhaps just thoughtless, security move destroyed the ability to use Firefox in a fully functional way as photographers had done previously for many, many years. Too bad for us photographers. But, who cares about us, eh? So, now off to investigate using some other browser that actually might be fully functional for looking at photographs, including my own.