How to delete message not written by admin

[NewMexiKen]

A new user mistakenly posted repeated messages improperly formatted -- did not embed images properly and kept trying and sending. I cannot delete the redundant erroneous messages, and so far the poster has not deleted them. How do I get rid of them? I should add that I get an error message referring me to this support forum for assistance.

[haozwang<Nabble>]

If you are an admin you can click on “more” drop down on the post and choose to delete post

[GregChapman]

And if you get an Error 500 you should post the full text of the error message - sometimes very long to this forum so Nabble can investigate the cause.