Quick Product Updates for osc 2.3+ in Add-Ons Development Posted August 10, 2020 1 hour ago, nedragdnuos said: Warning: Use of undefined constant TABLE_TAX_CLASS In general, when you see errors of this form TABLE_SOMETHING in regards to SQL, the fix is to go through and replace " . TABLE_TAX_CLASS . " with tax_class And yes, it is deliberate to remove the quotation marks and periods when doing that. Before the code was concatenating the constant into the string. Now the constant is gone and you just put the table name directly into the string. "select tax_class_id, tax_class_title from tax_class order by tax_class_title" Note that this means that the App was last updated prior to the 22.214.171.124 release. So we're two .0 versions past the change being made that broke this. And we're even further past the start of the change, which actually predates Phoenix. I mention this because unless you have budget to get this updated professionally, you might find that there are other issues that are not current in the code. This just being a particularly visible instance.