I don’t think the slash is the problem if that were the problem the files would not even appear in the skipped files list. If I am translating the message as to why your files have been skipped correctly then is the problem.
Audio Stream Format Not Supported - The file is may be valid, but Roon doesn’t support this format. It might use an unsupported codec (for example, an MPEG4 file with a .m4a extension where we couldn’t locate an AAC or ALAC track), use an unsupported sample rate or bit depth, be a video file, or otherwise be a type of media that Roon is not prepared to handle right now.
Is there something different about these files compared to those that have been imported? I think @dylan might want to have a look at some of them.
Yesterday I received an enclosure with USB cable (10Gbs) for my SSD drive. I replaced the old cable and connected the SSD drive, started Transporter and Roon … it started loading my entire music library. When it was finished I looked at the skipped files list: completely empty. So it was not a Roon / iTunes problem but just a malfunctioning cable that pretended to work well (data was visible).
I want to thank everyone for thinking along and helping with a solution.
Roon is working properly now !!!