I'm trying to undeploy an application in Tomcat manager web UI but not success.
I've deleted all .war files and folders in both webapps and work/catalina but when I list application, I still can see it on the list. Tomcat say "OK" but the application cannot be remove. Can someone tell me why, please?
You have a form of memory leak. The application (or possibly a library it is using) has opened a file but failed to close it. The open file(s) and any directories that contain it/them can not be deleted. Tomcat therefore auto deploys them as a new web application on the next auto deploy check.
Work-arounds / solutions depend on exact Tomcat version (which you failed to state in your question).