In the past, cTAKES was discussed in phpBB forums. Apache mailing lists are now used instead. If you are not modifying cTAKES beyond just configuration then subscribe to the user's mailing list. You can also just look through or search all discussion in the Apache mailing lists. See the Mailing Lists page to find links to the archives.
It may be of use to search the old forums as many questions about past releases (2.5 and before) have been asked and answered there in the cTAKES User forum.
Submit issues using JIRA. Anyone may read the issues. You must be a contributor to add or edit issues.
See the cTAKES Type System Diagram below: