We could't connect because there are currently no available resources. Try again later or...

[LucaBerniniKT]

Since this morning we receive this error when we try to connect to our application through the Remote Desktop Application: 

We could't connect because there are currently no available resources. Try again later or contact technical support.

And this is the error retrieved with powershell:

ErrorSource : RDBroker
ErrorOperation : OrchestrateSessionHost
ErrorCode : -2146233088
ErrorCodeSymbolic : ConnectionFailedRDAgentBrokerConnectionNotFound
ErrorMessage : RD Agent from host 0929c773-0c0a-4e02-9ac3-7fd74f6ac183 is not connected to the Broker instance is associated with during orchestration
request.
ErrorInternal : False
ReportedBy : RDGateway
Time : 8/12/2019 6:54:35 AM

We also tried to recreate the app group without success.

[#2]

@LucaBerniniKT I have similar problem and I can see the the agent on the session host is not posting heartbeats properly to WVD they way it used to. Did you resolve your problem? 

[#3]

@LucaBerniniKT Same problem in our environment. Yesterday we were using it, and this morning we are getting this error. Nothing has changed in between. Something down on Microsoft's end?

[#4]

@Johan_ErikssonUnfortunately not yet. We will try to delete and recreate the resources. 

[#5]

@LucaBerniniKT Solved the issue on my end!

I checked the status of session hosts in my environment, and noticed something odd.

PS C:\WINDOWS\system32> Get-RdsSessionHost -TenantName contoso.ca -HostPoolName contosoWVD

SessionHostName : contosoWVD-0.contoso.ca
TenantName : contoso.ca
TenantGroupName : Default Tenant Group
HostPoolName : contosoWVD
AllowNewSession : True
Sessions : 0
LastHeartBeat : 7/3/2019 8:41:18 PM
AgentVersion : 1.0.833.5
AssignedUser :
OsVersion : 10.0.17763
SxSStackVersion : rdp-sxs190429002
Status : Available
UpdateState : Succeeded
LastUpdateTime : 7/3/2019 8:38:18 PM
UpdateErrorMessage :

SessionHostName : contosoWVD01-0.contoso.local
TenantName : contoso.ca
TenantGroupName : Default Tenant Group
HostPoolName : contosoWVD
AllowNewSession : True
Sessions : 1
LastHeartBeat : 8/13/2019 12:37:59 PM
AgentVersion : 1.0.1006.2006
AssignedUser :
OsVersion : 10.0.17763
SxSStackVersion : rdp-sxs190614002
Status : Available
UpdateState : Succeeded
LastUpdateTime : 8/6/2019 8:08:11 PM
UpdateErrorMessage :

Our environment only has one session host. The other host "contosoWVD-0.contoso.ca" was probably one of our testing iterations early on. The strange part is that it was marked as "Available" even though it doesn't exist and last heartbeat was 7/3/2019. This must be a new bug starting a few hours ago. After removing the defunct host, it worked again. Traffic must have been routing to the old host in error.

Hope that saves someone the hours I spent on it this morning.

[#6]

@LucaBerniniKT Borked on us too after Windows Updates were installed this afternoon. Get-RdsSessionHost indicates the last heartbeat was received right before the VM was rebooted to install updates. KB4512508 is the culprit - I uninstalled it but the agent was still messed up. Dropped the Session Host from the host pool, uninstalled all the Remote Desktop agent stuff, followed the instructions for registering a session host to an existing pool via powershell, and got it working again after a reboot. Going to pause updates for a bit until a new agent comes out.

[#7]

@AS_Streamline  I am having the  same problem.