Why do I received a Licensing error 5008?

This only happens when I use the Parallel Computing Toolbox.

I followed the instructions given here:

https://www.mathworks.com/matlabcentral/answers/1819030-why-do-i-receive-the-error-you-are-not-licensed-to-use-r20xxy-when-i-try-to-launch-matlab?s_tid=oll_mwsh_paz_5008_maca64

It worked as I have a valid license. But after the Parallel Pool is deactivated, it happens again when I tried to use it again.

I just started using this MATLAB version, and it worked fine before this.

[Torsten]

Actionable Fix:

Licensing Error 5008 in MATLAB occurs when your parallel workers fail to check out a license. To resolve this, ensure you are signed into the correct MathWorks Account in MATLAB, and ask your License Administrator to link your account as an End User to the active license.

The most effective troubleshooting steps for resolving this error when launching a parpool are outlined below:

1. Verify MathWorks Account Linkage

Error 5008 often appears when MATLAB Parallel Server or Parallel Computing Toolbox requires online licensing, but your MathWorks account is not authorized.

• Action: Go to the MathWorks License Center to verify your profile has been granted access.
• Ensure you are signed in via MATLAB (Top-right corner -> Sign In) using the identical email that has the license privileges.

2. Check for Missing MATLAB Parallel Server

Often, a single-user PC only has the Parallel Computing Toolbox activated, but the cluster or worker profile is attempting to pull an enterprise MATLAB Parallel Server license.

• Action: Verify that the full MATLAB Parallel Server is correctly installed on all worker nodes or cluster nodes.

3. Clear Corrupt Preferences & Cache

Bad local cluster data or temporary corrupt license files frequently block parallel worker communication.

• Run prefdir in the MATLAB command prompt to find your user preferences folder.
• Navigate to the local_cluster_jobs or local_scheduler_data folder (usually located one level up from prefdir).
• Delete or rename these directories, then restart MATLAB and try starting the parpool again.

4. Verify Local Network & Firewall Settings

If you are using a network license manager, the worker nodes must be able to communicate with the central license server.

• Ensure your desktop or server firewall is not blocking the ports utilized by FlexLM and the MATLAB License Manager.
• Action: Ping the license server's IP address from your worker nodes. If it fails, a DNS or network connectivity issue is preventing your workers from checking out the license.

For further technical assistance or to open a support ticket with the MathWorks engineering team, visit the MathWorks Support page.