With some releases of KeyLAB you will need to upgrade all the computers connecting to KeyLAB and some releases you will not. This article will explain when an upgrade will be needed.
The way to find this out is to look a the second number in the version number before you install it. If the second number is an increment higher then you will need to upgrade all the computers running KeyLAB.
If you were upgrading the versions above then you will need to upgrade all the computers at once.
The above version would not need to upgrade all the computers at once.
If you don't follow this rule when you upgrade the first example the computers running the older version will not be able to connect to KeyLAB.
Its good practice to make sure all system running KeyLAB are running the current version ( the latest version on the website).