Dimension - access creative cloud account

it tends to be a licence issue at the Adobe server end,

for example lets say you log into Photoshop from a different computer some time last year... Adobe server logs that system and now thinks you are trying to use Dimension from more than 1 devive, even though it was Photoshop and your Dimension doesn't tell you any useful info about the failed login

Sing out and sign in again into your Creative cloud account. Are you using personal or enterprise account?