Strange error in 2.02 Advanced

i have recently installed 2.02 Advanced and created everything from scratch so new DB... every now and then i go to save a page and get this error

Your browser sent a request that this server could not understand.
Size of a request header field exceeds server limit.
Cookie: PHPSESSID=riblt2gueeups2k98us67qbv26; ys-modx-element-tree=a%3As%253Aundefined%5Es%253A/root%5Es%253A/root/n_type_chunk; ys-modx-file-tree=s%3 etc. etc....
Apache/2 Server at xxxxxxxxxxxx-internet.com Port 80

if i go to the website its fine, i then cant log in because of this error message, i clear my history cookies and cache and completely close my browser (using firefox, safari and ie8)


any ideas?


thanks

Have no idea, unfortunately! But I do have the same error. Gonna open issue ticket

There is already a ticket for this issue: http://bugs.modx.com/issues/4726