OMG I'm freaking out. Created a Powerpoint document yesterday on my Mac and saved it to a USB at about 11am. Kept working and hit "save" again when I stopped at 5pm. This morning, I realized the pptx didn't save at 5pm as it had the usual message that I can't save the file on the USB under that filename (won't let me overwrite files for some reason so I have to keep saving under different filenames). Before I saved it properly, I pulled the screen towards me, accidentally pulled the power plug out of the back and now the only file I can find is the 11am one. Is there any way of recovering this? Any help greatly appreciated.