"n.value.map is not a function" is returned when filtering a Test Execution by "TestRun Executed by" and "Assignee" filter options

Short Description: "n.value.map is not a function" is returned when filtering a Test Execution by "TestRun Executed by" and "Assignee" filter options.

Steps to Reproduce:

1 - Go to a Test Execution issue with some tests in it.

2 - Open the Filters dialog, add the option "TestRun Executed By" and filter by it.

3 - Do the same for "Assignee" option.

Actual Results: An error is displayed "n.value.map is not a function".

Expected Results: The filter option should work and no error should be displayed.