Resolve Error 1721 encountered during installation or upgrade of Portrait Dialogue


Following error message is encountered while installing or upgrade the Portrait Dialogue:
Error 1721.There is a problem with this Windows Installer package. A program required for this install to complete could not be run. Contact your support personnel or package vendor.


This could be caused due to either of following reasons:
1) 32 bit flag is not enabled in the Application pool used.
2) Application pool is not pointing to supported .Net Framework.


UPDATED: December 19, 2017
1. Check for IIS 32 bit application is enabled on you system.
  • Navigate to Administrative tools -> IIS Manager -> Application Pools.
  • Select Advance settings.
  • Refer following screenshot.
Screenshot IIS 32 On 64
If not then:
  • Open a command prompt and navigate to the %systemdrive%\Inetpub\AdminScripts directory.
  • Type the following command: cscript.exe adsutil.vbs set W3SVC/AppPools/Enable32BitAppOnWin64 1
  • Press ENTER.
Note: Ensure that the IIS application pool used to run the Dialogue Web Applications is configured with a Managed Pipeline Mode of Classic. By default, Dialogue Web Applications use the DefaultAppPool application pool.

2. Ensure Application pool uses .Net version supported (as mentioned in section 'Installation pre-requisites' in Portrait Suite installation guide) by Portrait Dialogue.
To know this, Navigate to Administrative tools->IIS Manager->Application Pools.