Well thanks for trying to help here, although, that's self-explanatory: everyone knows this already.
For All the new guys! out there on MPGH I have noticed many peopel are asking about the invalid link error just so you know that means the attachment has not been approved yet and before you guys start asking about that error I am gonna tell you how to know if it has been not approved: You will see text that says Attachments Pending Approval above the attachment that means you need to wait for an Admin/Administrator too approve it.
Please Sticky this!