After an in-place upgrade of Remote PC VDA's from version 5.6.400 to 7.6.300 keyboards would fail to map in ICA sessions from non-Windows Receivers such as Mac, Linux, and HTML5. 

3 distinct resolutions exist: 

#1 A re-install of the VDA will update the HKLM\Software\Citrix\Install key to point to the proper C:\Program Files\Citrix 

#2 Copying the contents of C:\Program Files\Citrix\HDX\Drivers\wdica to C:\Program Files (x86)\Citrix\HDX\Drivers\wdica will also resolve the issue 

#3 A private fix (LC4681) is also available that updates WDICA.sys to look in the proper registry key (HKLM\Software\Citrix\Install\ICAWS) for the install path of the VDA. This fix is planned to be incorporated in 7.6 CU2.

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Problem Cause

During the upgrade of a VDA, the previous install path is used in setting the "Location" install key in HKLM\Software\Citrix\Install. If the upgrade is from 5.6.400 this Location key is set to C:\Program Files (x86)\Citrix. If the prior install was 7.6 this key is set to C:\Program Files\Citrix. 

The WDICA driver incorrectly looks at the HKLM\Software\Citrix\Install key to determine the install path. Other drivers use HKLM\Software\Citrix\Install\ICAWS which will be set to C:\Program Files\Citrix even on an upgrade. WDICA uses the install path to locate KDB files which are used for Unicode Keyboard mapping required by non-Windows clients. 

In the event of an upgrade from 5.6.400 to 7.6.300 WDICA is unable to locate the KBD files which are located in C:\Program Files\Citrix\HDX\Drivers\wdica since it is looking in C:\Program Files (x86)\Citrix\HDX\Drivers\wdica. As a result keyboard mapping for non-Windows clients will fail. 

After an in-place upgrade of Remote PC VDA's from version 5.6.400 to 7.6.300 keyboards would fail to map in ICA sessions from non-Windows Receivers such as Mac, Linux and HTML5.