Event ID - 15

Event Id	15
Source	Microsoft-Windows-TerminalServices-Licensing
Description	This Terminal Services license server could not notify other Terminal Services license servers that new Terminal Services client access licenses (TS CALs) have been installed and added to its licensing database. If the problem persists, free up available memory if memory is low on the Terminal Services license server, and identify and resolve any network connectivity issues, specifically with firewall configuration. Problems with remote procedure calls (RPCs) might also cause this issue.
Event Information	According to Microsoft : Cause : This event is logged when Terminal Services license server could not notify other Terminal Services license servers that new Terminal Services client access licenses (TS CALs) have been installed and added to its licensing database. Resolution : Increase available memory (if necessary) or check firewall settings and fix network connectivity issues To resolve this issue, increase available memory on the Terminal Services license server if needed. If the problem persists, check firewall settings. If the firewall settings are correctly configured or the problem persists, identify and fix network connectivity issues. To perform these tasks, refer to the following sections. Increase available memory One way to increase the amount of available memory on the license server is to determine if there are any programs or processes running on the license server that can be closed. Use Task Manager to determine which processes are using the most memory, and to end those processes. To perform this procedure, you must have membership in the local Administrators group, or you must have been delegated the appropriate authority. To free up memory on the license server: On the license server, right-click an empty area of the taskbar, and then click Task Manager. Click the Processes tab. Make sure that the User Name and Memory (Private Working Set) columns appear. If they do not appear, on the View menu, click Select Columns, select the User Name and the Memory (Private Working Set) check boxes, and then click OK. At the bottom of the tab, select the Show processes from all users check box. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue. To sort the processes by memory usage, click the Memory (Private Working Set) column header. Determine if you can end any of the memory-intensive processes. To end a process, click the process name, and then click End Process. Click End Process to confirm that you want to end the process. If you cannot free memory by using Task Manager, or if this issue still occurs after you try to free up memory, restart the license server. If the issue persists, you should consider adding more memory to the license server. Check firewall settings To resolve this issue, check firewall settings to ensure that RPC communication is not blocked between the Terminal Services license server and other license servers. If the firewall settings are correctly configured or the problem persists, identify and fix network connectivity issues. Note : License servers maintain information about the location of other accessible license servers, and if those license servers have Terminal Services client access licenses (TS CALs). In certain cases, license servers will notify each other when TS CALs are added to their databases, or when they have no remaining TS CALs to issue. To notify each other, there must be network connectivity between the license servers. To perform this procedure, you must have membership in the local Administrators group, or you must have been delegated the appropriate authority. To check firewall settings: On the license server, click Start, and then click Control Panel. Click Security, click Windows Firewall, and then click Change Settings. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue. In the Windows Firewall Settings dialog box, click the Exceptions tab. Under Program or port, ensure that the Terminal Services Licensing Server check box is selected. If the Terminal Services Licensing Server check box is not selected, select it, and then click OK. On the other license servers, click Start, and then click Control Panel. Click Security, and then click Windows Firewall. Click Change Settings, and then, in the Windows Firewall Settings dialog box, click the Exceptions tab. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue. Under Program or port, ensure that the Terminal Services Licensing Server check box is selected. If the Terminal Services Licensing Server check box is not selected, select it, and then click OK. Note : To view more detailed information about Windows Firewall settings, use the Windows Firewall with Advanced Security snap-in. Identify and fix network connectivity issues To identify and fix any network connectivity problems between the license server and other license servers, do the following: Determine if there is a network connectivity problem by using the ping command. Perform additional troubleshooting steps, if necessary, to help identify the cause of the problem. To perform these tasks, refer to the following sections. Note : The following procedures include steps for using the ping command to perform troubleshooting. Therefore, before performing these steps, check whether the firewall or Internet Protocol security (IPsec) settings on your network allow Internet Control Message Protocol (ICMP) traffic. ICMP is the TCP/IP protocol that is used by the ping command. To perform these procedures, you must have membership in the local Administrators group, or you must have been delegated the appropriate authority. Determine if there is a network connectivity problem To determine if there is a network connectivity problem between the license server and the other license servers: On the license server, click Start, click Run, type cmd, and then click OK. At the command prompt, type ping server_FQDN, where server_FQDN is the fully qualified domain name (FQDN) of another license server and then press ENTER. At the command prompt, type ping IP_address, where IP_address is the IP address of another license server, and then press ENTER. If you can successfully ping another license server by IP address, but not by FQDN, this indicates a possible issue with DNS host name resolution. If you cannot successfully ping another license server by IP address, this indicates a possible issue with network connectivity, firewall configuration, or IPsec configuration. Perform additional troubleshooting steps The following are some additional troubleshooting steps that you can perform to help identify the root cause of the problem: Ping other computers on the network to help determine the extent of the network connectivity issue. If you can ping other servers but not the other license servers, try to ping the other license servers from another computer. If you cannot ping the other license servers from any computer, first ensure that the other license servers are running. If the other license servers are running, check the network settings on the other license servers. Check the TCP/IP settings on the local computer. In Device Manager, check the status of the network adapter. To open Device Manager, click Start, click Run, type devmgmt.msc, and then click OK. Check network connectivity indicator lights on the computer and at the hub or router. Check network cabling. Check firewall settings by using the Windows Firewall with Advanced Security snap-in. Check IPsec settings by using the IP Security Policy Management snap-in.
Reference Links	Event ID 15 from Source Microsoft-Windows-TerminalServices-Licensing

Catch threats immediately

We work side-by-side with you to rapidly detect cyberthreats
and thwart attacks before they cause damage.

See what we caught