Hi @wendycape,
check if the iiq.properties file is wellformed and the connection string is correct. If you are in a dev enviroment and you dont need any cert to connect to db, try to add this at end of the connection string:
encrypt=false;trustServerCertificate=false;
Also, be sure to have the correct version of the driver and it is compatible with java and MSSQL version. Try to use mssql-jdbc-12.8.1.jre11.jar and put id in WEB-INF\lib.
Check the permissions of the user on the identityiq folder, the same user that run tomcat must have the full access on this folder.
Like last test, stop the process and check if the process is really stopped, sometime the process still running with error.