Login to NPM issue - error ProfileCommon cannot be cast to ProfileCommon

Overview

This article discusses the issue when logging in to NPM, you receive the following error:

 ProfileCommon cannot be cast to ProfileCommon

Error Instance: 5958655544a140569d0800ffd5a1d98d
User: sritchie
URL: http://myportal.firstcomm.com:80/Ori....aspx?ViewID=1
Referrer: http://myportal.firstcomm.com:80/Ori....aspx?ViewID=1
Message: [A]ProfileCommon cannot be cast to [B]ProfileCommon. Type A originates from 'App_Code.1hed1_vs, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' in the context 'Default' at location 'C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\root\6faafa1c\92094bad\App_Code.1hed1_vs.dll'. Type B originates from 'App_Code.t2s4vagw, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' in the context 'Default' at location 'C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\root\6faafa1c\92094bad\App_Code.t2s4vagw.dll'.
ErrorSite: App_Web.Orion_SummaryView.get_Profile
ErrorType: System.InvalidCastException

You may also receive just a blank white screen, but you will find a similar error in the c:programdata/solarwinds/logs/orion/orionweb.log

Environment

NPM version 11.5.x

Cause 

The issue occurs when the local Orion disk drive space is down to 2.3GB free space. There's also a possible v4.0.30319 temporary files corruption.

Resolution

1. Log into the Main Orion server with the local Administrator account (do not use a Domain Admin account) to avoid GPOs and any other permission issues.
2. Delete all (except for the SolarWinds folder) C:\Windows\Temp folder.
3. Delete files from C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files.
4. Grant the servername\<athenticated users> and <network service> full rights to the following folder and all sub dirs:

   C:\ProgramData\Microsoft\Crypto folder
   C:\Windows\Temp\SolarWinds
   C:\ProgramData\SolarWinds

  5.  Run C:\Program Files (x86)\SolarWinds\Orion\OrionPermissionChecker.exe. 

  6.  Click Check.

  7. Click Repair. 

  8.  Delete all unnecessary files/folder from C:\ drive or add more disk space to your drive.

  9.  Run the Orion Configuration Wizard.

 10. Select all three option (Database, Services and Website), and follow the prompt. (Sometimes repairing just the web-site will do)

 11. After the Configuration Wizard completes, wait for five minutes before launching the Orion Web Console.