Blank Screen when setting order to "UPDATE"

[booghaboobaby]

Site has the latest code but we wanted the "order export" feature that the old site had from when we'd installed the zen cart order manager add -on module which we never got working. I added it again to the upgrade and we now have that feature back but when we set an order to UPDATE and only to update we get a blank screen. Setting an order to "shipped" or "delivered" etc works perfectly fine. We only get the blank screen in firefox. IE gives you:
The website cannot display the page
HTTP 500
Most likely causes:
- The website is under maintenance
- The website has a programming error
What you can try:
- Refresh the page
- Go back to the previous page
More information

Anyone have any ideas why it does this to the "update" function only?

[haredo]

Read this tutorial please.

https://www.zen-cart.com/tutorials/index.php?article=82

Look here for the error log to which .php file is affecting this: root directory/ cache