You have a nil object when you didn't expect it!
You might have expected an instance of Array.
The error occurred while evaluating nil.+

Extracted source (around line #16):

13:   <tr>
14:     <td><%=h employee.last_name %></td>
15:     <td><%=h employee.first_name %></td>
16:     <td><%=h employee.jobs_payable %></td>
17:     <td><%= employee.id %></td>
18:     <td><%= link_to 'Show', employee %></td>
19:     <td><%= link_to 'Edit', edit_employee_path(employee) %></td>