Did you invite your colleagues and/or third parties to work with you in TrueNxus?
Has it been more than 24 hours since you invited them?
If your answers to the above questions are yes, the issue at hand is that invitations are only active for 24 hours. However, you can resend them a new invite with a few simple steps.
Within the sidebar, click the Settings icon.
Within the Settings dialog, on the left navigation, click "Password". Click the button, "Edit Users".
Click the drop-down arrow next to Members. Then, click "Pending".
Identify the invited colleague (or a third party) and click the link, "Resend Invite".
You're all done. A confirmation will display in the bottom-left of the screen and an email has been sent to the invited user that will be active for 24 hours. Let your colleague or third party know that they should have received a new invitation.