@[deleted]Well, after authenticating I go to the tasks part, I see the list of created tasks, I enter one of these and I add 1 or 2 participants, I try to make a Post Update, at this moment the participants appear as recipients option that comes selected and that's where the error is generated, if I remove the selection in the recipients option, the Post Update is completed correctly.As for the Side Note: I do not understand what it means when it says instance. I understand that it is the installation of osTicket, if it is this, I have made certain modifications but nothing related to the part of the tasks so far.