If you are experiencing logon issues with a captcha or a page that displayed "500 - Uh oh! something went wrong on our end"  Please try some of the following solutions.   

Clear your browsers cache and any remove any XCOEX related cookies 

Try another browser or an icognito window to see if the issue persists, if it does not, you'll need to try clearing your cache and cookies again 

For Captcha, you can try VPN software that changes the geographic location of your IP address