error while traversing with activated fs watcher / inotify

Ok, the first “unexpected” happening:

2017-12-12 00:35:30: Failed to start filesystem watcher for folder "foo" (foo): error while traversing "/volume1/foo/folder/F/Foo & Bar": no such file or directory

This is a WebGui Message, I received on a Syncthing “v0.14.41, Linux (64 bit)” after a restart of the Syncthing service via WebGui.

The folder complained about is a folder, I recently deleted (or renamed). Maybe at the same time, the server was indexing after the restart.

While I see no harm here, I don’t understand, why I’m getting this message in the WebGui. What will it tell me I have to do?