Siemens SIMATIC HMI Series System Manual page 206

Licensing
7.7 Diagnostics of Licensing Problems
The "License.Log" and "LicenseLog.xml" diagnostic files
The "License.Log" and "LicenseLog.xml" diagnostic files display the licenses called by WinCC.
If a license is missing, a corresponding entry is shown.
The files are located in the WinCC installation path in the "diagnose" folder that is automatically
set up when WinCC is run for the first time.
Note
If the license for a WinCC option in use is missing, WinCC switches to demo mode.
See also
WinCC in the Demo Mode (Page 201)
206
WinCC: General information and installation
System Manual, 02/2017, A5E40840020-AA