when adding multiple files (especially if an external application opens an audio composition in xfburn), if one or more files for some reason triggers this issue, the dialog should inform the user which file(s) could not be added to the composition. Also, since the dialog only appears once, even if multiple files are at issue, the wording should be changed to "these files" where applicable. This issue applies to Xfburn 0.5.4 (which isn't a listed version number in bugzilla?)
This has also been reported in Fedora bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1408329 Users have reported that building from current git HEAD works. Any plans to release 0.5.5 anytime soon?
Soon I hope :)
If should be fixed in 0.5.5.