For troubleshoot Citrix licensing issues we may need to monitor license check-ins and checkouts. The logging of check-ins and checkouts is disabled by default. We can edit the Citrix.opt file located in the C:\Program Files\Citrix\Licensing\MyFiles or C:\Program Files (x86)\Citrix\Licensing\MyFiles folder and add a pound sign (#) to the NOLOG OUT and NOLOG IN statements as:

#NOLOG OUT
#NOLOG IN
Save the file.

Citrix Servers may take a long time to recognize changes that have occurred on the license server or we have a problem where users are not able to login while Presentation Server is not connected to the licensing server or license server changes take long time to propogate, we need to check MPS-WSXICA_MPS-WSXICA.ini file.
When the IMA service on a XenApp Server starts, it contacts the license server to get the license information from the farm. IMA then caches this information locally to the MPS-WSXICA_MPS-WSXICA.ini file on the XenApp Server. This file contains product licenses, number of connection licenses, expiration dates and remaining grace period. By default, the XenApp servers poll the license server every 5 minutes. However, they only check to see if the license server is alive. The cached license information is actually updated every hour. If IMA is busy or unresponsive on a XenApp Server, it is not able to update the cached license record during that interval.

CtxLicChk is a License Server monitoring tool, a command line utility to test the License Server ability to dispense a license to a XenApp server.
We can leverage this tool as a Citrix Health Monitoring and Recovery Test to get alerted, if there is a license checkout problem.
Usage:
CtxLicChk <LicenseServer> <LicenseType>
Example:
CtxLicChk 10.1.2.3 MPS_ENT_CCU