Estimated hours field for parent task is disabled on issue edit
For parent tasks estimated_hours filed is disabled on issue edit - we can not modify old estimation or even set new. Since v3.1 estimated_hours is no longer sum of subtask estimation, there is no reason to block this field for edit. For me for example it is much easier group task and estimate whole group rather than all tasks independent - it is impossible right now.
#4 Updated by Robert Korulczyk about 6 years ago
You're right, this issue was caused by https://www.redmine.org/plugins/redmine_archive_issue_categories . My bad.