Pop/Click Sound at end of MP3

I'd first remove the APEv2 tags:

  1. Goto File → Options → Mpeg and enable only APE under remove and press OK
  2. Select the files and remove the APEv2 tag via File → Remove tag or Ctrl+R

Then, again at File → Options → Mpeg, enable everything under Remove and make sure to disable reading and writing of APE if you don't use that and/or have obvious problems with other apps.