When you are invited as a bidder to a tender, you will receive an email where you can accept or decline the invitation.
In the same email, the login and password are clearly highlighted in yellow.
It is essential that you use these codes to log in and access the specific tender materials.
If you cannot see the current tender when you log in, it is likely that you are using an old password and login.
You should therefore log out and log in again using the correct codes from the email invitation.
Be aware that some browsers automatically remember your login. This can result in logging in with the old codes again. Make sure to disable the "remember me" function when logging in to view the new tender materials.