Activation errors, etc. in the SLP Runtime (aka Microsoft.Licensing runtime) can be diagnosed by looking in the error log file, "slp.log". Details of exceptions or other problematic conditions that happen during runtime execution are contained in this log.
Log File Location
The log files are created in the Temp folder of the user running the license application i.e. in %USERPROFILE%\AppData\Local\Temp
Distributor Log File Location
In the case of Distributor the slp.log file is located in the Temp folder of the account under which the Distributor service is running. By default Distributor is configured to run under Local System account and so the default location of the slp.log file is the Windows Temp folder i.e. in C:\Windows\Temp.
View Log File
To quickest way to view the log file is to do Start|Run and then enter:
Via Code Protector
If you are on a development box, start Code Protector and select Tools|Show Log. (Code Protector also allows you to clear the log via Tools|Clear Log.)
Via License Admin Utility
If you are redistributing the License Administrator, you can start it on the end user machine and select Tools|View Log File. (You can also clear the log via Tools|Clear Log File.)