Hello,

Once comments are able to be edited or deleted, it will lead to some troubles. :( Image that if you sent a task to your contact with a comment attached, your contact received it, and had done as the comment said before you edited or deleted, what would happen? He may be feel confused and didn't know what he should do.

Therefore, when you find there is something wrong in your comment, you can immediately add another comment to tell your contact that the previous one is ineffective.

We will appreciate it very much if you could understand.

Shall you need any help or have additional questions, please feel free to contact us.

Thank you for your feedback and support.

http://redmine.doitim.com/issues/7382