Thank you for using PTC Community! As we check your web account, its mapped with Siemens Industry Software LTD. It looks like your company does not have an active global support agreement. So you are unable to open a case.
Please check within your organization if you'll have an active support agreement and SCN(Service contract No.) with PTC. If so, please open a web account case to update your account with the correct/active SCN details. After this you should have access to open support cases.