Quote Originally Posted by burtonte View Post
... I'm not a web site developer or hard core programmer ... I just upgraded to v4 with zen cart 1.5.1. When I did I was very careful to merge the core files ... When (I) try to add an order from admin -- blank screen. ...
A "blank screen" in Zen Cart means a problem occurred. There WILL in most cases be a log of the issue. The starting point for diagnosing any problem is to locate any log file (Zen Cart debug log). The contents of the log files will usually tell you where (and why) a problem occurred and allow for troubleshooting. This log would be useful to the volunteers here at the Zen Cart forums (to help us help you).

Zen Cart does not natively (out of box) support creating a new order from the administrative interface. What "modification" are you using to "create" a new order using the Zen Cart admin? Name + Version + Link would be useful. If errors are occurring there is a good possibility something is not quite right with either the 3rd party module or the installation of the 3rd party module.

In a "stock" Zen Cart 1.5.1 installation, there is no code around line 81 of "/includes/classes/order_total.php" which looks like what you are describing. I am going to guess you (or someone else) made modifications to the file (introducing an issue)...

Edit Orders 4.1+ requires "/includes/classes/order_total.php" to properly load under both the catalog (store front) and admin interface. If order total modules or other processing are "excluded" via a check like the one you are describing other errors and miscalculations may occur. I would not recommend disabling portions of this critical module loader (as it appears your line of code may)...

NOTE 1: I would strongly suggest rechecking your upgrade to Zen Cart 1.5 and make sure all the core files were updated / merged correctly. Typically when upgrading Zen Cart one starts with clean files from the new version of Zen Cart, determines what alterations (if any) have been made to the old files, and only (if needed) applies the "changes". Doing a full merge can cause issues...

NOTE 2: Edit Orders 4.1+ includes a "slightly" modified version of "/includes/classes/order_total.php" designed to allow the "stock" (and most other) order total modules to load from the administrative side of Zen Cart. The one supplied with Edit Orders 4.1+ can directly replace the stock Zen Cart 1.5 version of the file.