You can't use the login form because buttons and/or text fields labels are missing:
Cause
Javascript was disabled.
Solution
Windows 10 and 8
- Click Search.
- Enter Internet Options.
- To enable Javascript on the Security tab, click Custom level > Scripting > Active scripting and then click Enable.
Windows 7
If you're still using Internet Explorer 8, please update to Internet Explorer 11, even if Internet Explorer isn't your default browser.
- Click the Windows button to open the Start menu.
- Click Control Panel.
- Click Network and Security.
- Click Internet Options.
- To enable Javascript on the Security tab, click Custom level > Scripting > Active scripting and then click Enable.
A faster option is to reset your settings: