OpenLM provides a mean to monitor Flexnet publisher license denials. Please see this document for clarification. It does so by extracting information from the FlexLM debug log file.
Denial reports may not appear in the FlexLM debug log if the application’s option file contains a NOLOG line, with a DENIED flag. If this is the case, edit the option file to exclude this flag, and restart the license server. See this document for more information.