After Project Server migration from one farm to another, you receive an error "This Web Part was unable to load”

Issue Description

I had done a migration of Project Server environment from one farm to another. (Database detach-attach).And some of the users had the below issue when trying to access the (Project Details Pages) PDP pages.

This Web Part was unable to load.

Information that may be useful in solving this problem was written to the Unified Logging Service (ULS) log on the Project Server with the following ID:

18c06eca-de62-4544-b11a-c3440ada01e9

This problem can occur in other ways also, such as:

1) You cannot create or edit projects in PWA.

2) You cannot open Project Details Pages in Server Settings.

I checked the ULS logs with the error id and was able to fix this issue.

Cause
The PWAURL property is set to a PWA site, but none identified yet.This should be null.

Resolution

Open SharePoint PowerShell and run the below commands:

$Web = get-SPWeb http://servername/pwa

$Web.AllProperties | Format-Table

The output of the second command will show if PWAURL was set to a URL (not expected) – if so then you can change this back to NULL again using PowerShell

$Web.AllProperties[“PWAURL”]=””

$Web.Update()

Reference

ULS Log

                                                                                                                                                                                                                                                                                                                                                Web Part Exception Unique ID: 18c04eca-de79-4585-b92a-c3960ada01e9 System.NullReferenceException: Object reference not set to an instance of an object.     at Microsoft.Office.Project.PWA.WebParts.ProjectFieldPartBase.GatherAndLoadCFList(Boolean bForceRefresh)     at Microsoft.Office.Project.PWA.WebParts.ProjectFieldPartBase.RebindGrid(Boolean forceRefresh)     at Microsoft.Office.Project.PWA.WebParts.ProjectFieldPartBase.PWA_OnLoad(EventArgs e)     at Microsoft.Office.Project.PWA.WebParts.PWAResiliencyPart.OnLoad(EventArgs e)          611d75ae-a62e-46c4-b3a9-b9311f4dc02a

w3wp.exe (0x1584)                                      0x1558      Project Server                             Unified Logging Service                c91s          Monitorable                Watson bucket parameters: Microsoft Project Server 2010, ULSException14, 070f6ea0 "project server", 0e001b67 "14.0.7015.0", 17ecd0fa "microsoft.office.project.server.pwa", 0e001bc2 "14.0.7106.0", 51eed0b6 "tue jul 23 14:51:34 2013", 00000c29 "00000c29", 00000077 "00000077", 4a6d3421 "nullreferenceexception", 63653972 "ce9r"               611d75ae-a62e-46c4-b3a9-b9311f4dc02a

w3wp.exe (0x1584)                                      0x1558      Web Content Management            Publishing                                   7fz3          Medium     Setting [Display] as the FormContext.FormMode for the current page    611d75ae-a62e-46c4-b3a9-b9311f4dc02a

w3wp.exe (0x1584)                                      0x1558      Web Content Management            Publishing                                   7fz3          Medium     Setting [Display] as the FormContext.FormMode for the current page    611d75ae-a62e-46c4-b3a9-b9311f4dc02a

w3wp.exe (0x1584)                                      0x1558      SharePoint Foundation                  Topology                                    e5mc         Medium     WcfSendRequest: RemoteAddress: 'http://servername:32843/d248615527544dfe8f90663b61673ee2/PSI/PWA.svc' Channel: 'Microsoft.Office.Project.Server.Interfaces.IPWA' Action: 'http://schemas.microsoft.com/office/project/server/webservices/PWA/AdminReadSiteMapTyped' MessageId: 'urn:uuid:a6cfcb4c-e800-4687-92cc-e7367ea735b0'         611d75ae-a62e-46c4-b3a9-b9311f4dc02a

w3wp.exe (0x15BC)                                      0x13FC      SharePoint Foundation                  Topology                                    e5mb        Medium     WcfReceiveRequest: LocalAddress: 'http://servername.abc.com:32843/d248615527544dfe8f90663b61673ee2/PSI/PWA.svc' Channel: 'System.ServiceModel.Channels.ServiceChannel' Action: 'http://schemas.microsoft.com/office/project/server/webservices/PWA/AdminReadSiteMapTyped' MessageId: 'urn:uuid:a6cfcb4c-e800-4687-92cc-e7367ea735b0'         611d75ae-a62e-46c4-b3a9-b9311f4dc02a

w3wp.exe (0x15BC)                                      0x13FC      SharePoint Foundation                  Monitoring                                  nasq          Medium     Entering monitored scope (ExecuteWcfServerOperation)         611d75ae-a62e-46c4-b3a9-b9311f4dc02a

w3wp.exe (0x15BC)                                      0x13FC      SharePoint Foundation                  Monitoring                                  b4ly          Medium     Leaving Monitored Scope (ExecuteWcfServerOperation). Execution Time=6.5183       611d75ae-a62e-46c4-b3a9-b9311f4dc02a

w3wp.exe (0x1584)                                      0x1558      Project Server                             General                                      ce9r          Exception   Web Part Exception Unique ID: 18c04eca-de79-4585-b92a-c3960ada01e9 System.NullReferenceException: Object reference not set to an instance of an object.     at Microsoft.Office.Project.PWA.WebParts.ProjectFieldPartBase.ReplacePlaceHoldersWithCustomFieldControls()     at Microsoft.Office.Project.PWA.WebParts.PWAPart.PageLoadCompleteInternal(Object sender, EventArgs e)    611d75ae-a62e-46c4-b3a9-b9311f4dc02a

w3wp.exe (0x1584)                                      0x1558      Project Server                             Unified Logging Service                c91s          Monitorable                Watson bucket parameters: Microsoft Project Server 2010, ULSException14, 070f6ea0 "project server", 0e001b67 "14.0.7015.0", 17ecd0fa "microsoft.office.project.server.pwa", 0e001bc2 "14.0.7106.0", 51eed0b6 "tue jul 23 14:51:34 2013", 00000c09 "00000c09", 00000011 "00000011", 4a6d3421 "nullreferenceexception", 63653972 "ce9r"               611d75ae-a62e-46c4-b3a9-b9311f4dc02a

w3wp.exe (0x1584)                                      0x22A4      SharePoint Foundation                  Monitoring                                  nasq          Medium     Entering monitored scope (Request (POST:http://abc.xyz.com:80/PWA/_vti_bin/PSI/Workflow.asmx))