Bevel modifier not working on one object I have been trying to round the corners of an object. I used the suggested bevel modifier as per (How to round corners of plane?). However it did not work for me so I tested it in a new file on a similar object and it worked just fine. Can anyone tell me why it would not work on the appended object in the linked file?
Modifiers don't work properly when an object is scaled.

Your object has scale 0.005.

After you Apply scale CtrlA, the bevel will start to work.