Hi Trent,

So there was a significant change between 14.1 and 16.1, sometime around 15.2 where if you didn't enable the respective "Require ExtJS v3.4.1 to be loaded on each page" and the "Require ExtJS v3.x based Client API be loaded on each page" options within the Site Settings of the Admin Console, you would have to insert in a helper like LABKEY.requiresExtClientAPI.

So if you enable those checkboxes in Site Settings, you will not need to use those dependencies within the code itself.

Site Settings under Admin Console - https://www.labkey.org/wiki/home/Documentation/page.view?name=configAdmin
Declaring Script Dependencies - https://www.labkey.org/wiki/home/Documentation/page.view?name=scriptdepend
Namespace for LABKEY (with all the existing dependencies you can call) - https://www.labkey.org/download/clientapi_docs/javascript-api/symbols/LABKEY.html

Regards,

Jon