I'm having problems with a 2016 onprem and the Sandbox service I hope someone can help with.
To illustrate my problem I have a plugin, that creates a contact, every time an account is updated.
The plugin is registered in sandbox mode, and this is a requirement in the environment as this is a shared hosted platform.
The system consists of 4 servers, all with at least frontend and sandbox services installed.
When updating my account I get random errors saying "he communication object, System.ServiceModel.Channels.ServiceChannel, cannot be used for communication because it is in the Faulted state.", meaning the CRM Service is faulted.
When looking at the traces I can see that this happens when a sandbox service is trying to access CRM on a different server. If accessing locally, the request works. I believe this is due to a SPN problem, but I have created SPN records for the sandbox user on all server names, both with and without domain name. Also the Sandbox user is in the Priv User group.
I'm missing something here, but have hit a dead-end on where to go, so any suggestion on what to do, or how to continue my debugging would be appreciated.
/Peter