In VDA server, if MacBook Device name longer than 15 characters, there is an issue on renew RDS cals License. The eventlog has a 1028 warning with TerminalService-RemoteConnectionManger. Hence the user cannot use the XenApp normally.

Here are 3 workarounds, you can choose one of them.
#1. reinstall the workspace app in the client --> it will recreate a new Client hardware id.
#2. rename the client name <= 15 characters. --> it may need to revoke the previous license.
#3. In the site db, using SQL command to find the client hardware id. Then delete related registry key in VDA
Example: 
1. find all:
select EndpointName, EndpointAddress, EndpointHardwareId from [CitrixLabSite].[chb_state].[Sessions]
2. find specific client:
select EndpointName, EndpointAddress, EndpointHardwareId from [CitrixLabSite].[chb_state].[Sessions] where EndpointName = 'xxxxxxxxxxxxxxxxxxxx'

Then you can find the registry key in the all related VDAs: 
For example, the EndpointHardwareId is 0F339F7D

1. find the key: HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\MSLicensing\BUCKET_7d.
2. In the BUCKET_7d, you can find the LICENSE_0 is match the hardware id.
3. delete the key: HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\MSLicensing\BUCKET_7d\LICENSE_0

 

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Problem Cause

This is a limitation with current design.
If the client host name is longer than 15 characters, there is problem of RDS per-Device license renew.

For non-Windows client (Mac or Linux client), if license is checked out by RD Session Host server from RD License server, RDS CAL is stored on RD Session Host server. Since RDS CAL is not stored on non-Windows client, when this client connects to another RD Session Host server it cannot send the RDS CAL that the other RD Session Host server needs to relay to RD License server. 

To facilitate MS Licensing and RDS CAL replication, avoid extra RDS license allocated, ICA creates the registry entry.