1. If some courses have changed and they want u to adjust to the recent change.
2. If there were any technical issues as at the time u registered and they have adjusted it eventually and they want u to adjust also so that there won't be problems now or in the nearest future.
3. If u underpaid or overpaid some funds and the price has later changed (e.g. some students paid N3,000 for their projects but now the money has eventually increased to N15,000 and they want you to pay the new money, you might fall into this)
4. If there are any technical issues whatsoever with your portal or with ur registration.
To know if u fall under this category, just log into your portal and click on courses and follow those steps described in the post... If u find that error message, then u have to go to the school ICT department to reset ur portal. If u could view ur registered courses and exams successfully, then u don't have any problems at all.
To reset your portal takes just one button at the Ict department. Once this is done, u will have to rewrite all ur TMAs and submit again.. Cos all the TMAs will be gone. When u register ur courses and exams, u will be able to write the the TMAs again