There's not really enough information to tell anything, but one problem I often have suggests itself based on the topic title.
If you have been starting Tomcat as ROOT, Tomcat has created a number of files owned by ROOT. If you then attempt to start as user "tomcat" - or any other non-root user, then the Tomcat startup will fail because it's attempting to create and/or access files that user "tomcat" is not permitted to access or change.
Science is the process of replacing what we "know" with what is TRUE. Politics, alas, often prefers to be the opposite.
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