"Error, Check Activation" when trying to add an ebook through a acsm link.

Hi! I have problem adding an ebook which I just bought. When I try to add it through the acsm link it only says "Error, Check Activation".

I have authorized my computer earlier, but I have changed my computer setup since then, and I guess that is an issue. I am unable to erase authorization to make a new one, it says "Unable to Eraze Autorization. Please try after some time." every time I try to erase.

I guess I need to edit registers to delete the authorization? Or is there anything else I can do?

Kind regards

Tomas