Insufficient audio quality.

Unfortunately, one or more of your tracks does not meet the requirements to be considered of sufficient quality.
Insufficient audio quality includes unwanted noise, overdrive/clipping, volume jumps, and audibly poorly converted audio files.
Please rework your audio files and then replace them with the tracks you have already created.

To do this, proceed as follows:
1. Click on "MUSIC" on the left side of your Feiyr account.
2. Select "Releases"
3. Click on the edit icon in the last column
4. Click on step 4 "Track Upload" at the top of the progress bar
5. Scroll down and search for the corresponding track
6. Now you can click on the "upload track" icon (hard disk with arrow pointing up) on the right side in the tasks column and exchange the improved audio file
7. Once the track is finished uploading, you can republish the release.