"the edb.log is the log file for Windows.edb file. Since Windows.edb itself is a database file for Windows Search service that provides content indexing, property caching, and search results for files, emails, and other contents; the edb.log file will contain all the information about activities done by Windows.edb."
Taking an educated guess that those database files are locked and in use, and Network Discover is unable to scan them. I would exclude them from scans.