lat9:
That function (zen_get_products_manufacturers_id) is not a "standard" Zen Cart function. I suggest that you use your admin's Tools->Developers Tool Kit to find where it is defined on the storefront. Once found, you can create a copy of that function for use in the admin, creating a .php file in /admin/includes/functions/extra_functions to 'hold' that function's definition.
Thank you for your reply! Much appreciated. I was able to easily fix this issue by changing mock shopping cart to false, per the documentation.
However, I now have another issue. If I try to add a discount coupon to the order total, it works perfectly, but if I try to add an additional discount or charge, the module won't do it. Like I mentioned in my previous post, I use Table Discounts, and I forgot to mention I also use Priority Handling 1.3.0 for an optional rush charge to every order. If I try to apply either a rush charge or a discount, I get a "Success: Order has been successfully updated." but the charge won't appear. The funny thing is that there is no error message in the logs, and the edit order log does not even show that I was attempting to add an extra charge.
2019-07-10 15:18:15, Edit Orders entered (4.3.5) action (edit)
Enabled Order Totals: ot_subtotal.php;ot_table_discounts.php;ot_coupon.php;ot_tax.php;ot_shipping.php;ot_priority_handling.php;ot_total.php
getOrderInfo, on entry: Called by /home2/xxxxxx/public_html/xxxxxxxx/admin/edit_orders.php on line #705
Subtotal: (not set), Shipping: (not set), Shipping Tax: (not set), Tax: 0.00, Total: 26.18, Tax Groups: {"0.0000":"1"}
$_SESSION['shipping']: {"title":"Shipping (UPS - UPS: Ground ($10.22) (1.75Lbs))","id":"advshipper_","cost":10.22}
Order Totals
ot_subtotal. Text: $19.95, Value: 19.9500
ot_coupon. Text: -$3.99, Value: 3.9900
ot_shipping. Text: $10.22, Value: 10.2200
ot_total. Text: $26.18, Value: 26.1800
Checking order for virtual status. Order contains 1 unique products, 0 of those are virtual
getProductTaxes(Tax)
{"products_tax_class_id":"1"}{"qty":1,"id":"537","name":"Columnar Sheet Double Page Ruling 24 Columns White<br><br>1021-2","model":"1021-24","tax":"0.0000","price":"19.9500","final_price":"19.9500","onetime_charges":"0.0000","products_priced_by_attribute":"0","product_is_free":"0","products_discount_type":"2","products_discount_type_from":"0"}
getProductTaxes, returning 0.
calculateOrderShippingTax, advshipper does not provide tax-information.
calculateOrderShippingTax returning 0.
getOrderInfo, on exit:
null
Subtotal: 19.95, Shipping: 10.22, Shipping Tax: 0, Tax: 0.00, Total: 26.18, Tax Groups: {"Tax":0}
$_SESSION['shipping']: {"title":"Shipping (UPS - UPS: Ground ($10.22) (1.75Lbs))::","id":"advshipper_","cost":10.22}
Order Totals
ot_subtotal. Text: $19.95, Value: 19.9500
ot_coupon. Text: -$3.99, Value: 3.9900
ot_shipping. Text: $10.22, Value: 10.2200
ot_total. Text: $26.18, Value: 26.1800
Checking order for virtual status. Order contains 1 unique products, 0 of those are virtual
============================================================
= Creating display of Order Product #46936
============================================================
Product Details:
{"qty":1,"id":"537","name":"Columnar Sheet Double Page Ruling 24 Columns White<br><br>1021-2","model":"1021-24","tax":"0.0000","price":"19.9500","final_price":"19.9500","onetime_charges":"0.0000","products_priced_by_attribute":"0","product_is_free":"0","products_discount_type":"2","products_discount_type_from":"0"}
I did notice in the newer version that there is now a dropdown menu with items from our order totals modules, as opposed to the older version that we were using which only had blank fields. An additional question would be if there was an easy way to either add items to that dropdown or get rid of it altogether and have blank fields so our CSRs can type whatever they want and not depend on what modules are present in our order totals list?

Once again, thank you!