This occurs if the SAP user does not have sufficient access to the downloads function.

Login as a user with higher access priveliges or, to give the user access:

1. Open SAP and click Tools, select Password & Security then click Access Groups .
2. Select the relevant group and click Edit.
3. Expand Client/Datasets and select Check Internet for Updates. 
   The user now has the option to check for updates from the Help menu.