If you are getting this error when accepting a google adwords invite then follow these steps to fix the problem; 1. Create another dummy google account, say, dummy@gmail.com 2. Sign out and sign into google adwords using your primary gmail account, say, primary@gmail.com 3. Invite dummy@gmail.com and grant an administrator role 4. Sign into your dummy@gmail.com account and accept the invite. 5. Go back to your primary@gmail.com adwords account and confirm the acceptance by dummy@gmail.com by clicking on Grant button. 6. Sign out of adowords account and sign in again using dummy@gmail.com . Delete primary@gmail.com from your adwords account. 7. Go back to your adwords invite and accept using primary@gmail.com account. This time it should go through without any errors. To summarize, you have to transfer the ownership of your current primary gmail account...