Hey Nazar,
I understand that you are trying to change the license server for all your machines as your current license server does not exist anymore.
I am not sure if the following will help you change the license server for all machines at once, but changing the license server for individual machines can be accomplished in 3 ways. You may try these out to see if these are helpful.
1) Replacing the license files MATLAB uses.
2) Setting an environment variable to point to a new server.
3) Launching MATLAB using the -c flag.
Method 1
MATLAB clients will have a license file located in $MATLAB\licenses (R2008a or later) or $MATLAB\bin\win32 (windows) or $MATLAB/etc (Linux/Mac). This file consists of a SERVER line, and a USE_SERVER line. To retarget the client, replace the SERVER line with the new SERVER line from the new manager, save the file, and start MATLAB.
Method 2
During MATLAB's startup, it checks the environment variables "LM_LICENSE_FILE" and "MLM_LICENSE_FILE". To launch MATLAB using a license from a new server, set an environment variable with either of these names to a value using the syntax {port}@{hostname} of the license server, where {port} is the number at the end of the SERVER line, and {hostname} is the resolvable name of the license manager.
For example, if the Network License Manager had a server line that read as follows:
SERVER licenseserver1 001122aabbcc 27000
the environment variable value should be set as
LM_LICENSE_FILE=27000@licenseserver1
In the example above licenseserver1 is the hostname, 001122aabbcc is the Host ID (in this case, a physical/MAC address), and 27000 is the port number.
Method 3
When launching MATLAB, you can also force it to use a particular license by using the -c flag. The argument that follows -c can be in the form of a path to a license file or using the <port>@<hostname> syntax mentioned above. For example:
matlab -c 12345@licenseserver
On Windows machines, you can modify the target field of the MATLAB shortcut as follows for a similar effect:
"C:\Program Files\MATLAB\R2022b\bin\matlab.exe" -c 12345@licenseserver
Hope this helps!