License not valid

Hi,

We are using Avast Business Security (18.5.2535). One of our users is getting a notification to say her license is not valid and she should contact the Admin (me). However there does not seem to be any option to Activate a license. This user and pc have been happily installed for over a year, and other users are not affected.

Does anyone know what is causing this and how it can be resolved?

Thanks
Peter.