Q: I am getting the following error:
The requested URL returned error: 401 Unauthorized

A: You may have updated the module from version 3 to version 4. Beginning with version 4.0.0, this module uses Petfinder API v2.0. You will need to enter your Client Secret in the module configuration settings. You can find your Client Secret by signing into Petfinder for Developers, then selecting Developer Settings from your profile menu.