If Salamander is choking or throwing an error on specific MP3 files when trying to read them (especially when loading the metadata columns or using the file viewer plugin), it's almost always due to corrupt or malformed
ID3 tags. Before looking for a deeper bug in the manager itself, it's worth checking if the files themselves are the culprit. You can use a quick web editor like
https://editmp3tags.com/ to open one of the problematic files, clean up or strip the tags, and see if Salamander handles it fine after that.