Google Chrome

1. On your computer, open Chrome.
2. At the top right, click the menu icon : and then Settings.
3. At the bottom, click Advanced.
4. Under \"Privacy and security,\" click Content settings.
5. Click Cookies.
6. Under \"All cookies and site data,\" click Remove all.
7. Confirm by clicking Clear all.
8. Close chrome and reopen. Try logging in again. 

Safari

1. On your computer, open Safari.
2. Click on Safari and then on Preferences.
3. Select Privacy and then click Manage Website Data.
4. Select Remove All and then in the small popup, selection Remove Now.
5. Click Cookies.
6. Under \"All cookies and site data,\" click Remove all.
7. Confirm by clicking Clear all.
8. Try logging in again. 

Google Chrome

1. On your device, open Chrome.
2. Tap the menu icon :
3. Go to Settings.
4. Go to Privacy, and then tap Clear Browsing Data.
5. Check what you want to delete from the list, and then choose Clear Browsing Data.
6. Tap Clear Browsing Data again to confirm your decision.
7. Try logging in again

Safari

1. Open Settings.
2. Scroll down to Safari.
3. Scroll down to Clear History and Website Data, and select it.
4. A pop-up message will appear, notifying you that this will remove the data from your device and other devices signed into your iCloud account. Tap Clear History and Data to confirm.
5. Try logging in again.