You can run multiple License Servers on the same machine, provided they are for different vendors. Multiple License Servers from the same vendor are not supported.
If you have multiple licenses from the same vendor, they can be combined into a single license.dat file, however to avoid conflicts this must be done by LDRA licensing. A single instance of the License Server can then serve all licenses contained in that file.
When running License Servers for multiple vendors on the same machine, ensure that each vendor uses a unique port number.
Port conflicts can prevent one or more License Servers from starting correctly.
See Configuring ports for more information on specifying ports.