Thanks for your patience.
A temporary fix I have found is:
1. Sign-in to your blogger account
2. Go to design tab, you'll get the bX-l4u1mh error here, surprise!!!
3. Click Template Designer, the blogger template designer will load.
4. click Layout, and you can edit your page elements now :)
There are three ways to fix this problem.
1. Change Your Browser.
2. Clear all Cookies,History,Index.dat Files(Please save your important links or downloads before deleting)
3. Reboot your system after deleting cookies.
1. you log in with google chrome to your dashboard blog and go to page elements.
2. Log out from your account.
3. Log in again but use different browser this time like mozilla, EI,Opera. and go to page elements.
4. log out, use google chrome again to login and go to page elements .
5. your page elements blog is now fixed.