I have been working with zencart for a year now. And one of the problems I have encountered is the admin page can not be browsed properly. I also have such problem in the product page. I can not be able to customize my cart because of this. any help? or tip?
Might you edited some codes in admin dir? Try to replace with original files but backup it before replacement.
Hard to say without seeing things. Have you installed anything lately? Blank pages are usually a result a minor syntax error if not an extra space in a relevant php file. Nigel