1. Delete "C:\Program Files\Apache Software Foundation\Tomcat 9.0\webapps\multiterm.war" and also folder "C:\Program Files\Apache Software Foundation\Tomcat 9.0\webapps\multiterm"
2. Copy this multiterm.war "C:\Program Files\Apache Software Foundation\Tomcat 9.0\webapps\multiterm.war"
3. Restart Tomcat 

If it does not work, check Tomcat config Java option box if the following options are available:

-Djava.library.path=C:\Program Files\SDL\SDL Server\SDL Multiterm\Multiterm16
-Dorg.apache.el.parser.SKIP_IDENTIFIER_CHECK=true