Symptoms
In BA customer control panel (CCP), after pressing Buy More Services on Home screen the following error appears:
System Error
No access rights granted to method
On Account screen in CCP there is no Buy More Services link at all
Cause
CUST_PURCHASE_SERVICE privilege, that is needed for service purchase is not included in corresponding user's role
Resolution
Add CUST_PURCHASE_SERVICE privilege to user's role. The absence of this privilege in role can be caused by manual changes or by some misconfiguration, which needs to be investigated additionally.