We have upgraded Tomcat from 9 to 10.
This is a major change that requires code changes.

If you have an existing Greenstone, and you have done an 'svn update' on it,
then you will need to run (at a minimum):
ant prepare-tomcat
ant copy-dot-svn-files
This also runs check-resources-timestamps, which will fail as there are some new .svn files. Keep checking each file it shows up, then re-run ant check-resources-timestamps
ant clean-core
ant compile-core

Note, the code before the Tomcat 10 commits has been branched at https://svn.greenstone.org/main/branches/tomcat-9

Tomcat 10 uses new versions of its web.xml, context.xml and server.xml - If you know you have made mods to any of these please check your resources/tomcat/*9.xml.in versions against the *10.xml.in ones.