The error indicator in the tray icon should ignore system-generated files, including temporary Office files. I had a perpetual "2 items can't be synched" message, but after clicking through to the report, it indicated All files are up to date." It took running the repair tool to discover that the only 2 files with issues were temporary MS-Office files, which use invalid chars in their naming ("~$<filename>.<ext>"). Once the repair tool renamed the files and the system was restarted, the tray icon returned to normal. A case was opened with PSS, who recommended reporting to UserVoice although this is a bug/issue rather than a feature request (#30099-1365727 / 716653).