Assign Resource on Tasks - poor performance and error "Unable to communicate to the PM Server"

Products

• Clarity PPM On Premise
• Clarity PPM SaaS

Issue/Introduction

I am trying to add a resource to a task and the system is returning error message:
"Unable to communicate to the PM Server. Please try again and if problem persists contact your system administrator."

Steps to reproduce:

1. Click on the impacted project
2. Click on the task
3. Scroll down and click the assign button

Expected Results: Popup window should appear with list of resources that can be assigned to the task
Actual Results: The popup never appears for me and I eventually get the error mentioned above

Notes:
All resources with contractor type are added via task to this project, so there are a large number of team members
This doesn't appear to happen on all Tasks, only this one.  It does include many resources. 

Cause

• This can be due to one or more Attribute Value Protection (AVP) values being set at the highest level of:
  • 'Use display conditions and secured subpages to protect attribute values on this list' for an associated view. 
• If you don't use display conditions, it's recommended to use the AVP setting of: 
  • 'Use only secured subpages to protect attribute values on this list'
• Generating an action trace can help in narrowing down which query/action may be causing the issue to help in any further performance tuning
  • see steps to enable action trace at: KB000009353

Environment

Release : All Supported Releases

Component : CA PPM INTEGRATIONS & INSTALLATIONS

Resolution

• If you aren't using display conditions for the view, change the Attribute Value Protection setting for Resource Selection - List to:
  • 'Use only secured subpages to protect attribute values on this list'

Steps to update the setting below:
1. Go to Administration->Objects->Resource->Views
2. Click Options next to 'Resource Selection - List'
3. Change the Attribute Value Protection level to 'Use only secured subpages to protect attribute values on this list'
4. Save changes
5. Go to a task that doesn't have the issue first
6. Click the assign button
7. Click the Gear icon on this page then select Configure
8. Click the General tab 
9. Click Restore Defaults  (just to ensure the update gets pushed out to the user ID without any lag)

Additional Information

For On Premise customers, See KB 28825 if you would like to make this AVP Setting change across all views