I am working with Engineering to get a hotfix out for issues we've found with the KAV 1.2 to 1.3 update on the endpoints. So far the most common issue I've found in investigation is that the majority of the failed upgrades (hanging at reboot needed, processing stopping at uninstalling KAV, etc.) have been traced back to the endpoint having an out of date KaLua package. The KaLua package is the management tools needed for sending processes to the endpoint from the KServer.
We hope to have a hotfix available in the next few days, but in the mean time, check that the endpoints that you are attempting to update from KAV 1.2 (Kaspersky Antivirus 2010) to KAV 1.3 (Kaspersky Workstation 6) are showing the current KaLua version in the KAV module. The KaLua package version is noted either in the right hand pane as "Version" or in the Version column set, as the "Service Version" as noted in the screenshot below.
In the mean time until the hotfix is released, support can assist with forcing an update to the KaLua package to endpoints as needed.
TravisKaseya Senior Support Specialist
Has this been released yet? We are having this issue across 1500 endpoints.