Hi @Satoshi_Aoyagi,
Thank you for the report and we’re sorry to see that this persistent bug has reared its head in your database as well.
What you’re encountering is an anomaly related to Roon’s background indexing. This issue is highly specific to the library’s database and file structure/taxonomy, so it’s proven arduous to reproduce in-house. As such, we’ve released a series of fixes over the last few weeks to adjust the behavior preceding the triggers of the anomaly. We’re quite confident in this most recent fix, which has now been rolled out to a public Roon update in build 1528.
Please update your RoonServer to the latest build and let us know if this issue returns over the next several days. We’ll of course keep this thread open.