We are seeing the same issue. Except it is only impacting the Num Lock key. Even though the Num lock light is lite, users can't use the numbers from the right side keypad unless they press the num lock key as though they are turning it off and there is not light. Our current work around in the applications section of the horizon client is to change the protocol to PCOIP and selecting the check box underneath that section for Extend to local IME. We noticed this issue after upgrading to 5.4.2 Horizon client. The IME setting seems to force the use of the English keyboard on the local device in the session. Not sure why blast is thinking we have a non English keyboard on our RDSH hosted application servers. Everything is looking like we only have the English keyboard as the option.