Cannot install Exchange 2010 after installing Exchange 2013

Question

Hi,
I have the current setup as explained below.
Exchange 2010 SP3 Version 14.3 (Build 123.4)
I installed Exchange 2013 as well to the setup. After installation everything was fine, but my backup solution was not as good enough to support Ex2013. So, I had to roll back. I uninstalled Ex 2013.
On the new server (on which I actually installed EX 2013) I tried installing Ex 2010 but it failed. But, when I execute Get-ExchangeVersion I get these two.
  AdminDisplayVersion                     ExchangeVersion
  Version 14.3 (Build 123.4)              0.1 (8.0.535.0)
  Version 14.0 (Build 639.21)             0.1 (8.0.535.0)
The first one is the live Exchange 2010 ( The first one which we had). When I try to run the setup, I am getting the following Error.
Error:
The following error was generated when "$error.Clear(); get-OfflineAddressBook -DomainController $RoleDomainController | where { $_.IsDefault } | Enable-OabWebDistribution" was run: "Object is read only because it was created by a future version
of Microsoft Exchange: 0.20 (15.0.0.0). Current supported version is 0.10 (14.0.100.0).".
What can I do now? My intention is just to create another Exchange Server for redundancy. I only have one EXchange server now. I tried installing EX 2013, and it seems not suit me because of backup issue. What I have in my mind is to get 2 Ex 2010 Servers.
Should I try uninstalling EX 2010 and installing it from the beginning on the new EX Server?
Thanks

Answer 1

Hi Steve,
I have the same situation, On a new server (on which I actually installed EX 2013) I tried installing Ex 2010.
In the Client Access Role install setup, I getting:
Error:
the following error was generated when "$error.Clear(); get-OfflineAddressBook -DomainController $RoleDomainController | where {$_.IsDefault} | Enable-OabWebDistribution" was run: "Object is read only because it was created by a future version of Microsoft
Exchange: 0.20 (15.0.0.0). Current supported version is 0.10 (14.0.100.0)
Admin Display Version
server 1 version 14.3
server 2 version 14.0 (Client Access Role Error)
how can I resolve this error?
Thanks.
Regards.