Message
Server Side or Client Side
What it means
Solution
"-15 Cannot connect to license server system. The server (lmadmin or lmgrd) has not been started yet, or the wrong port@host or license file is being used, or the TCP/IP port or host name in the license file has been changed. Windows XP SP2 platforms have a limit on the number of TCP/IP connection attempts per second that can be made, which your application may have exceeded. Refer to the manufacturer's documentation on how to change this limit."
Client Side
This issue can be caused by several items:

1. No client environment variable created. See solution 1.

2. Wrong port or host specified in the client environment variable. See solution 2.

3. Client is unable to utilize the environment variable - need to add manually to the registry. See solution 3.
1. See section How to set Client Variable here: https://rtcllc.freshdesk.com/a/solutions/articles/43000063923

2. See section How to set Client Variable here: https://rtcllc.freshdesk.com/a/solutions/articles/43000063923

3. Manually add the Key and value to the Registry
  1. Go to Registry Editor.
  2. Browse to: Computer\HKEY_CURRENT_USER\Software\FLEXlm License Manager
  3. Create the String value: “FLEXRTC_LICENSE_FILE”
  4. Set the value to the environment value specified in the section How to set Client Variable here: https://rtcllc.freshdesk.com/a/solutions/articles/43000063923
 
LMTOOLS Installation Error 2502 and 2503
Server Side
This is a Microsoft Installation error
See these two links:




In addition to the 3 methods shown on the Microsoft page, I recommend trying the Microsoft Fixit tool.


“Bad message command”
Server Side
Our FlexNET Vendor Daemon uses FlexNET 11.14
Check to make sure your version of LMTOOLS is 11.14 or newer.
“Number of licenses exceeded”
Client Side
All licenses are in use and a valid connection to the Host server and FLEXRTC daemon is Up and running
Close your client product and another client product that is currently using a license, then reopen the product to obtain a license.
“Flex Message: Cannot connect to license server system. The license server manager (lmgrd) has not been started yet, the wrong port@host or license file is being used, or the port or hostname in the license file has been changed.”
Server Side
There may be something blocking a connection on your computer like Windows Firewall or no/limited LAN connection. Also may be the server is down or the FLEXRTC daemon FlexNET service has stopped on the server and needs to be started. Additionally, this could mean a poor connection to the server and a license is not returning quick enough.
Try to restart your computer. May need to set an exception rule on corporate firewall to allow pass through.
If accessing from multiple DNS or intranets, use the full DNS name in the license file on SERVER line and set Client Environment Variable to same full DNS name. ex. SERVER <server name>.domain.com and also try to use a "Time Out setting environmental variable" to set and allow time to connect: FlexLM_Timeout = 10000000
“License server is down or not responding…Hostname: server name” 
 
Client Side
Means the local settings may be wrong like a spaces after semicolon; in variable setting.
Revisit the Environment variable to ensure it’s set properly.
"FLEXlm Error -96. Server node is down or not responding."
Client Side or Server Side
This issue could be a few things causing it:

1) Initial settings of the firewall are set to block the communication between your local client machine and the FLEXlm license server. This means you will not be able to get a license without configuring the firewall. This can also mean the license service is Down or the Port that was set in the license is being used by another process. Check the LOG file on the server to see if any message is stated.

2) The service created was not established as a local system service.
1) The Windows or Anti-Virus software may need to allow EXE to pass through:

License Server:
Select Start->Settings->Control Panel.
In the Control Panel window, select Security Center and then Windows Firewall.
From Windows Firewall, select the Exceptions tab.
Under Exceptions, press the Add Program button and then browse to lmgrd.exe in the \FLEXRTC FlexLM directory. Then, press Add Program again and browse to FLEXRTC.exe in the \FLEXRTC FlexLM directory.

Client Computer:
Select Start->Settings->Control Panel.
In the Control Panel window, select Security Center and then Windows Firewall.
From Windows Firewall, select the Exceptions tab. Add the ACAD.exe to allow passing.

2) To update the service setting on your file server:
  1. Click the Windows Start button, Administrative  Tools, Services. For Windows 10, click Windows  Administrative Tools, Computer Management, Services  and Applications, Services.
  2. Find the name of your FlexNet Service that doesn't start.  Right-click the name and select Properties.  
  3. Click the Log On tab, then select Local System  account, then click Apply.  
  4. Click the General tab, then click the Start  button. The service should start in a few seconds.  
  5. Click OK, and close the Services dialog.
The service should now stop and start normally from LMTOOLS.

"The Desired vendor daemon is down"
Server Side
FLEXRTC.exe is not running on network server
First make sure that the FLEXRTC.EXE vendor daemon is running on the license server:
1. Open lmtools.exe
2. Pick the service to view (acad.exe)
3. Pick the Server Status tab
4. Pick the Perform Status Enquiry button

Scroll down to the line Vendor daemon status (on server)

If running: FLEXRTC: UP (lists current flexlm version)
1. If the vendor is DOWN, it will read cannot connect to license server.
2. Make sure no other services are using PORT 27000.

CAD Design Software issues network license files with the default port of 27000.
1. To check other services, return to the Service/License File tab
2. Pick a service
3. Pick the Server Status tab
4. Pick the Perform Status Enquiry button.
5. On the line License server status: port@server showing the current port assigned.
6. If it shows 27000@server, this would be the conflict.
3. You may change the port number in your FLEXRTC.LIC license file to a new port (see LIC note)
4. Open the FLEXRTC.LIC using notepad (see above).
5. On the server line SERVER server name mac address 27000
6. Change the port 27000 to another port that is free (example 27010) and then save and close the LIC license file.
7. Open lmtools.exe
8. Select the CAD DESIGN SOFTWARE service
9. Pick the Start/Stop/Reread tab
10. Pick the Stop Server button
11. Pick the Reread button (may say reread failed)
12. Pick the Start Server button
13. Pick the Perform Status Enquiry button
14. On the line License server status: 27010@server showing the new port assigned.
15. Scroll down to the line Vendor daemon status (on server)
16. Should now state UP
FLEXRTC: UP (lists current flexlm version)
17. Update the Environment variable on each client's computer to the new port number.
No message on PC. Computer cannot see server
Client Side
Something is blocking the port access from computers on the remote side of the server
A firewall must be blocking the port from the user side. See this link:

https://knowledge.autodesk.com/support/autocad/learn-explore/caas/sfdcarticles/sfdcarticles/Ports-used-by-Autodesk-Network-License-Manager.html

Note: If these port addresses are restricted by a router or firewall software, users on the remote side of the router will not have access to licenses controlled by the Network License Manager.


"Cannot open license file C:/Path/Licensefile.dat

EXITING DUE TO SIGNAL 43 Exit reason 20"

Server Side
LMTOOLS version is not high enough to support the Vendor Daemon
Download the latest LMTOOLS from Autodesk's site here: https://knowledge.autodesk.com/customer-service/network-license-administration/get-ready-network-license/download-the-network-license-manager

Log file shows something like:
12:02:38 (lmgrd) FLEXRTC using TCP-port 0
12:02:38 (FLEXRTC) SLOG: Statistics Log Frequency is 240 minute(s).
12:02:38 (FLEXRTC) tcp_s is bad!!! Exiting
12:02:38 (FLEXRTC) EXITING DUE TO SIGNAL 28 Exit reason 5
12:02:43 (lmgrd) FLEXRTC exited with status 28 (Communications error)
12:02:43 (lmgrd) Please correct problem and restart daemons

Server Side
Port is blocked or in use by something else.
Specify a different port in the license file.
https://knowledge.autodesk.com/search-result/caas/sfdcarticles/sfdcarticles/ET-Licensing-a-Perpetual-license-of-Arnold-for-Maya-2016.html

FlexNet Licensing Service is not installed or disabled.  Unable to establish requirement with RTC (Service Name).
Server Side
The service was marked for deletion but is still started.
Stop the service, remove the service from LMTOOLS.. add again and restart.
FlexNet does not report that Vendor Daemon is starting. Does not seem to start service. Perform Status Inquiry shows nothing. Debug log shows nothing   
Server Side
The Services was created with wrong administrative privileges.
To update the service setting on your file server:
  1. Click the Windows Start button, Administrative  Tools, Services. For Windows 10, click Windows  Administrative Tools, Computer Management, Services  and Applications, Services.
  2. Find the name of your FlexNet Service that doesn't start.  Right-click the name and select Properties.  
  3. Click the Log On tab, then select Local System  account, then click Apply.  
  4. Click the General tab, then click the Start  button. The service should start in a few seconds.  
  5. Click OK, and close the Services dialog.

The service should now stop and start normally from LMTOOLS.