Can suspend but not activate an instance

My colleague created an instance of Solman 7.2.  I can access the instance, successfully logging in to the Gui.

I can also suspend the instance from the CAL instances tab.  However, once the instance is suspended I cannot re-activate it (the 'activate' operation is visible, but not enabled).  I am an administrator for the instance.

Where to start looking ??

Cheers,

Guy