This can be caused by a number of possible issues, including, but not limited to the following:
- Network connectivity issues
- Insufficient computer resources or restrictions are placed on computer resources
- Licensing issues
Network connectivity issues
Make sure that each worker is able to communicate with each other over the network and that the appropriate ports are opened. If you don't know which ports should be opened, take a look at the link below.
How do I configure MATLAB Parallel Server using the MATLAB Job Scheduler to work within a firewall?
Please check your hosts file to make sure that any manual entries are added correctly. Entries added incorrectly can result in network connectivity issues.
Insufficient computer resources
Please make sure that MATLAB has the ability to access at least the minimum system requirements when validating your cluster. If you're unsure what the minimum system requirements are, take a look at the link below.
System Requirements
Licensing issues
It is also possible that there is an issue with the Network License Manager. There are several different types of Network License Manager errors, such as the Network License Manager being misconfigured, not running, or its ports are blocked. Check the Network License Manager for any faults. Otherwise, create a full validation report to see if you can find a License Manager error or a log file in the validation report.
