Installing Webclient application results in error "Version 11.5 of Progress WebClient must be used to run this application."

On updating a webclient application, the installer now prompts to update the version of webclient software even though it is the same one that is installed.  



The application has been packaged using the 11.7 64-bit Application Assembler and is to be deployed to an 11.5 32-bit installation.
The OpenEdge 11.5 32-bit webclient has been installed on the client machine, but when the double clicking the application .prowcapp file the error message is immediately displayed.  

The prowcapp file being used contains the ContinueOffline option set to true and the FormatVersion set to 5.0:

When the application was packaged in the Application Assembler the user selected the option to "Continue Offline".  This could be because the customer is trying to use new OpenEdge features (64-bit, Advanced UI etc), but these features cannot be used with an older OpenEdge Webclient version.  The error being displayed is highlighting that these new features cannot be used in OpenEdge 11.5.  The version number in the error message is taken from the WebClientVersion entry in the prowcapp file (which is specified in the “WebClient Version(s)” field on the “WebClient” tab in the Application Assembler).



In the Application Assembler selecting "Continue Offline" sets the "FormatVersion" field value to 5.0 regardless of other settings.  This option was introduced with OpenEdge 11.7 to allow Webclient execution when the Webclient is unable to refresh the prowcapp file. 

"Continue Offline" and other selected options, determine the value of the FormatVersion field.   The value of FormatVersion indicates which features may be enabled in the prowcapp file. The base version is 2.0 and this indicates that the prowcapp file is for a 32-bit application and doesn't use any of the following features:
 

• 64-bit application
• Advanced UI (.NET features - these can be enabled with Options tab -> System Tasks Definitions)
• Continue offline

The current possible values for FormatVersion are as follows:
 
The idea behind the FormatVersion field was to keep the prowcapp file as backward compatible as possible.  Subsequently the prowcapp file contains the lowest value of FormatVersion that covers the enabled features. This allows the user to create an application which will run with older versions of WebClient as long as the application doesn't use any of the newer features.

This table shows which features are supported by each value of FormatVersion. A checkmark doesn't indicate that an application with that FormatVersion must use the feature. It indicates that the application can potentially use the feature. Whether or not the application uses a given feature is governed by other settings in the prowcapp file.
 

FormatVersion	Supports 32-bit application	Supports Advanced UI features	Supports 64-bit application	Supports Continue offline
2.0	X
3.0	X	X
4.0	X	X	X
5.0	X	X	X	X

Repackage the application in the Application Assembler without checking "Continue Offline".  An OpenEdge 11.5 32-bit Webclient application should have a FormatVersion field set to 2.0 in the 'VersionInfo' section of the .prowcapp file.

References to Other Documentation:
OpenEdge Getting Started: New and Revised Features, Chapter 1: "What's New in 11.7", "WebClient improvements"