How to configure Complete and Take Next Activity

Enable Custom Sorting 

We need to select the 'Include complete and next button' option when generating a take activity form in order to see the 'Complete and Next' button,

By default, activities are sorted based on "ActivityDueDatePriority - Process activities in the order of activity due date and activity priority."
Please note the  CoreWorkerActivityOrder is for the Core Worker - this is the order that the Core Worker will process activities, and it doesn't have anything to do with the WorkQueue.

Functionality was added to the product in v7.5 to enable custom sorting,
This has to be enabled in the Designer - System Settings - Work Process,
In newer versions, this is enabled in Designer - System Settings - General - Enable custom sorting:

IIS, CoreWorker & Streaming services must be restarted after enabling the custom sorting

Create a Work Queue Query 

Create a new Work Queue Query so that you can choose what you want to sort on e.g. Process
The options we have to sort on are:

Give the Query a name and save it

Create Work Allocation Rules 

When we create the WorkQueue query that sorts, we can then create a Work Allocation Rule to use this WQ Query,

We create the Work Allocation Rule in the Workspace - Administration - Work Allocation Rules menu,
e.g. 

We then associate the Work Allocation Rule with our resource - this can be done via Designer:

Or Workspace (Workspace - Administration - Manage Resources):

For the next activity to work as expected,
Either the resource or the resource's working group must have a work allocation rule assigned
Note: Only 1 Working Group can be assigned to a resource, this can be updated/changed in the Designer/Workspace as required

A resource's Working Group can be configured in the Designer:

Or in the Workspace:

Take next activity should then work as expected