Can't login in admin

[pchulpleusden]

First of all, I would like to thank you all for such a great job on this CMS. I've used several CMSs, but this is by far the most easiest CMS i've used yet.

Unfortunately isn't GetSimple working well anymore. If I want to login at the admin login, I'm getting just a white page after filling in my username and password.

To find out what was happening I've set GetSimple to DEBUG-mode and it appears that the opened page: pages.php contains a couple of errors. The exact errors are in the text-document what I have attached.

The strange thing is that if i change the url to edit.php instead of pages.php, the page opens just normal. Then I get my menu back and it further works for all pages. I've also uploaded a new pages.php-file and a whole new admin folder, but it unfortunately doesn't work either.

I don't what to do further, because the strange thing is that I hadn't changed anything and at once it doens't work anymore. I hope you can help me further! Thanks in advance!

Website which contains the error:
http://www.pchulpleusden.nl/GetSimple_3.0/admin/

Login is in the attachment.