Problem updating Lightroom 6 to 6.6

I have full admin access on four different macs and can only select the LR 6.6 update on two of them.

On the other two computers the update dropdown tab is not highlighted, so I am unable to select it.

All four versions of LR 6 were registered with my Adobe ID.

I have full admin access on all four Macs, and all are running the same OS (El Cap). 

I am unable to update the two versions of Photoshop CS 5.1 on either Mac in question as well.

So to sum it up, two Macs update perfectly, and two of Macs will not allow the update.

The two Macs have some Adobe software (CS 5.1) that was registered by a long gone former employee.

I have contacted Adobe via chat and they suggest that all the solutions are within the forum community.

The contact information for the former employee has been updated to me via adobe chat and email.

All the serial Keys are with me but the two versions of Photoshop CS5.1 do not appear under my Adobe Account.

I think Adobe needs to transfer the registration of all the mentioned Adobe products to my Adobe account for the updates to work properly.