First of all check your time/date on the bottom right hand side corner is corrct or not ..... Since this is asecure login if your time and date is incorectly set you are automatically logged out or might experience problems while logging in

Secondly if your date/time is correct try reset your browser : Go to Tools--->internet options---->Advanced---->Reset

Third if the above two does not help check your antivirus or firewall is not blocking it ..... Try to restart your computer in safe mode : Turn computer off ----> Trn it back on and momemt yopu see a black screen coming up keep on tapping ( tap don't keep it pressed) F8 on keyboard till you see a screen with black and white options ----> select safe mode with networking and press enter -----> try to go on ebay now ............ To get back your regular desktop just restart normally