how to license vsphere 5.5 install using vsphere 6.0 license keys

[esmwebmaster]

We recently purchased a vSphere 6.0 Essentials license for a LAB environment but installed ESXi 5.5 and vCSA 5.5 on lab servers without applying licenses. We planned to start with vSphere 5.5 in LAB to mirror the existing production vSphere environment and then upgrade the LAB to vsphere 6.0 as practice/dry run for production upgrade from 5.5 to 6.0. However, we need to keep the vSphere LAB at vSphere 5.5 for few more months and now need to apply licenses to LAB servers since the eval period is about to expire. When trying to enter our vsphere 6.0 Essentials license keys to the Licensing interface in the vsphere web client, we get the error:

Cannot add the following license keys in your inventory

Invalid keys: XXXXX-XXXXX-XXXXX-XXXXX-XXXXX

License file not found

Fix or remove these keys to proceed

How can we enter and apply the vSphere 6.0 Essentials license keys to a vSphere 5.5 installation? We really don't want to re-build the LAB servers as there is important testing going on and we don't want to incur the delay for re-build.

Does anyone have an answer to how to license a vSPhere 5.5 installation using vSphere 6.0 license keys?

Thanks for any information you can provide.

[a_p_]

Login to your My VMware portal on which the licenses are registered. There you will be able to downgrade the license keys. Once you are ready to upgrade the lab, you can upgrade the license keys agin.

André

[esmwebmaster]

Just saw your response and I'll try this first thing tomorrow.

Thanks so much for the response. Looking forward to getting this license applied and moving forward with work.

Much appreciated.