I\'ve installed apache-tomcat-9.0.7 on my windows machine and have following environment configurations:
echo %JAVA_HOME%
C:\\Program Files
You need an update that isn't on the main Oxygen site. Add http://download.eclipse.org/webtools/repository/oxygen/ as a URL in your Available Software Sites preference page and then check for updates from the Help menu.
https://bugs.eclipse.org/533162
Edit: this fix will be properly included in the Photon (WTP 3.10) release later this month.