This message could not be moved to trash folder, possibly because your mailbox is nearly full.
In that case, please try to empty your deleted items first, or delete smaller messages first.
Cannot delete messages in inbox, spam, trash and all other folders appear to be empty. NOt getting new e-mails relaibly either
Try clearing out your browser's cache/browsing history. When you have done that, close out the browser and re-start it in a fresh session. If that doesn't do it, then try using a different browser. See if the same thing happens.