Hi Joe,
Many thanks for the reply.
I am fairly sure that I have a named user license. I access ArcPro via the enterprise login section.
Prior to this error I had requested access to Arc Pro offline.
As I am unable to open Arc Pro I am unable to edit my settings in the Portal - is there another way that I can access the portal?
Time settings on my PC seem to be as normal...
I have tried a complete uninstall - when running the additional microsoft utility that you provided I cannot locate ArcPro in the list of applications provided and therefore cannot run the utility as desired.
I have manually gone through the registry and removed all reference to ArcPro. Following a reinstall I now recieve an error stating that I am registered to use Arc Pro on another device and therefore still cannot log in.
I have spoken to the admin at my University, who have contacted ESRI. They have requested that my offline permissions be reset ( Do you know of a way I can do this myself?). Hopefully then I will be able to open Arc Pro and access the Portal - I will let you know if this solves the issue.
Do I have any other options that I can try in the meantime?
Many thanks again,
Hugh