ServerHealth on CasServer Healthset RPS.ProxyResource MSExchangePowerShellFrontEndAppPool Status Unhealthy

Hi,

our cas-Server reports an Unhealthy Healthset:

get-healthreport -server casserver| where {$_.alertvalue -ne "healthy"} | ft -auto
Server       State  HealthSet AlertValue LastTransitionTime  MonitorCount
------       -----  --------- ---------- ------------------  ------------
casserver Online RPS.Proxy Unhealthy  28.10.2014 10:42:57 1
and
$issues = Get-HealthReport -server casserver | where {$_.alertvalue -ne "healthy"}
foreach ($line in $issues) {$line.entries | where {$_.alertvalue -ne "healthy"} | ft -auto}
Server       State  Name                TargetResource                      HealthSetName AlertValue ServerComponent
------       -----  ----                --------------                      ------------- ---------- ---------------
casserver Online RPSProxyTestMonitor MSExchangePowerShellFrontEndAppPool RPS.Proxy     Unhealthy  RpsProxy

i can connect to OWA and ECP under https://localhost/owa and "https://casserver.domain.int/owa"

but i cant connect to https://localhost/powerShell/ and https://casserver.domain.int/powerShell

The Exchange Default Website and BackEnd have an SAN Cert with alle names in the cert:
CN = autodiscover.domain.int
DNS Name=autodiscover.domain.int
DNS Name=autodiscover
DNS Name=mail.domain.int
DNS Name=mail DNS Name=casserver.domain.int
DNS Name=casserver
DNS Name=mgmtcasserver.domain.int
DNS Name=cmgmtasserver
DNS Name=localhost
DNS Name=10.20.40.54
DNS Name=10.50.60.72

The PowerShell Directory Points to "D:\Exchange2013\ClientAccess\PowerShell"

Can anyone help?