@John-Couto What author? There are some bad actors who simply claim they are the rights holders. For example, they take the royalty free music and add their own vocals and upload it via a distribution service. Then other users, like you, get flagged with false copyright notices because you use the same music. The system is simply broken because it's all automated and the algorithm only compares the audio.

For all files included in Sound Forge Pro you can find the license information in the EULA. To my knowledge, pro-versions of Magix software usually allow non-exclusive commercial usage of the included assets. But this won't help to prevent false copyright claims.