“The list of RemoteApp programs cannot be accessed. Verify that the management console is connected to the correct server and that you have Administrator privileges on the server, and then try again.”

Checking winrm everything seems to be correct:

c:\>  winmgmt /salvagerepository
WMI repository is consistent

c:\> winmgmt /verifyrepository
WMI repository is consistent

But after resetting the repository, the remoteApp manager starts working again:

winmgmt /resetrepository

In order to avoid this error…

C:\> winmgmt /resetrepository
WMI repository reset failed
Error code:     0x80070005
Facility:       Win32
Description:    Access is denied.

you will have to stop the service previously.