Can't Login To Backend

[cricket-hockey]

Please help! I have an urgent problem.

 

Suddenly I can't login to Prestashop 1.6.1.2.

 

When I enter my username and password it just stays on the login page but without the username or password fields - see attached screenshot.

 

If I enable debug mode I get a blank white screen with the following message:

 

Strict Standards: Declaration of Link::getProductLink() should be compatible with that of LinkCore::getProductLink() in /home/cricket/domains/domain.com/public_html/override/classes/Link.php on line 413

 

I tried deleting the Link.php file completely but it still doesn't work.

 

Please, please could someone suggest what might be the problem?

 

 

 

 

[cricket-hockey]

I should add that I've cleared cache and cookies but that doesn't help. There are no errors on the console in Chrome, but looking at the source code the email and password login box is there in the code but not displaying on the screen.

 

I don't know if it is relevant but there is this piece of code in the head:

<script type="text/javascript">
var img_dir = '/img/';
var more_errors = 'There are several errors.';
var one_error = 'There is one error.';
</script>

[cricket-hockey]

Just an update - it has suddenly started working again. Bizarre as I didn't make any changes since last posting.