License error: 5 when adding vSphere 6 license to vCenter 5.x

By | March 25, 2015

Quick post.

This may be known to others, but since it’s been a few years since the last major vSphere came out,  I’m sure some others will run into this.


If you buy NEW licenses, they will come as vSphere 6, which is incompatible with a vCenter 5.

If you try to add the license you will see this error:

3-25-2015 12-33-36 PM



In order to fix the issue you need to downgrade the vSphere license

Go to the license portal, choose “I want to downgrade” and select the vSphere 6 license

3-25-2015 12-29-48 PM

Select the appropriate number cpus to change (in this case 4) and choose check the box

3-25-2015 12-30-51 PM


3-25-2015 12-31-29 PM


Pretty straightforward thing to do, just something that you may overlook as VMware moves on with new licenses while you are holding off on updating to the latest hotness.

7 thoughts on “License error: 5 when adding vSphere 6 license to vCenter 5.x

  1. Win

    After the key has been downgraded can we later use the original v6 key for a new server?

    1. Chris Post author

      That would be violating your licensing agreement. When you downgrade it says that you must destroy the old keys

  2. Matt

    Does this mean that you can’t add an existing, stand alone ESX 6 server to a 5.5 vSphere instance? I imagine after downgrading the license that it would no longer function for the esx 6 host.

    1. Chris Post author

      If you have a 5.x vcenter you should really upgrade since it’s not longer supported.

      This blog was about using a 6.x license with a 5.x host, downgrading the license to be 5.x.

      In the scenario you discussed, the 6.x host with 6.x license will not join to a 5.x vcenter. Hosts have to be at the same level of venter or lower (with some limits)


Leave a Reply

Your email address will not be published. Required fields are marked *