Did you check that at the end of the files there is no DC? When additional 'silence' helps then there most probably is.

I'm afraid I don't quite see how this is an issue of the UFX, if it's DC in the original files.

Regards
Daniel Fuchs
RME

and btw, files recorded directly in durec, do not click at the end !

what if someone has some music files on a USB stick and they want to play them back at a gig through a loud PA ? if you have 100 files are you supposed to sit there and make sure every file has zero crossing and proper fade out so the UFX doesn't make a large click sound ?  You can buy a $50 media player that wont produce click sounds at the end of WAV playback and yet the UFX cant do the simple job like a $50 media player ?

If you take average music files off the net and playback on UFX in my experience everything produces a click. When I first got the UFX I rendered a bunch of backing track sequences out of my DAW and all of them would produce this click sound.. In the end I had to manually sit there with 40 files and digitally edit the end of each one... at first a fade out wasn't enough until I ended up putting 5 seconds of rendered silence at the end after the fade out and the UFX finally stopped making the click sound. this turned into hours of editing just to playback the files without a click.

I can confirm this click with the latest firmware 1.61. I can provide the multichannel file that produces the click, separate 1 or 2 channels wavs were exported from Logic and  the multichannel wav was compiled in Audacity. The last samples should definitely have 0 values as is seen in Audacity.