'Authorisation' for Addins

Hi

we have a user who cannot access Lawson Addins on his machine though they are all there.  We have raised with IT but they believe the access is correct.  The login screen comes up (and the login is fine on portal) but the following pops up when trying to log in:

'You do not have authorisation to use the Lawson addins. Please contact your administrator'

Does anyone have any idea what this means?  If IT are saying access is fine, I am not sure where else ot look.  Next option is to remove addins and reinstall.

Thanks