Sometimes we need to scale out a CRM 2015 deployment that is having the latest update installed, when you try to join a new server you are faced with the below error in the installer checks page:
The Product key is not compatible with installed version of Microsoft Dynamics CRM.
I believe this is a bug in the installer so to workaround it add the IgnoreChecks registry key to the computer that is running Microsoft Dynamics CRM so the installation can proceed when an error is shown in the Environmental Diagnostic Wizard (EDW):
Click Start, click Run, type regedit, and then click OK.
In the registry, locate the following subkey:
Right-click MSCRM, point to New, click DWORD Value, and then type IgnoreChecks.
Double-click IgnoreChecks, and then type 1 in the Value data field.
Note: After including this registry value you will get the same error message in installation wizard but this time the Next> button will be enabled in Installation Wizard to complete this installation so just proceed and install the CRM latest updates at a later step.