Did you ever figure this out?  It looks like a complete reinstall for my server and all my workstations?  This is ridiculous.

Complete reinstall on server and 105 workstations, big PITA, and weird slowdown with My Assistant client included for free!

The new feature that updating the server updates the content of the WinInst installation at least worked, but that meant no scripting to distribute the patch at all.

40% of reinstalls failed for various reason, so a full install was required. I received no reports of the .DSK desktop configuration files changing, though, so there is that. 

Also, with many installs, after the installation is complete and the workstation reboots, the user account used for the upgrade MUST login again to let the installer scripts complete, or the start menu will be empty for the normal user of the workstation. I use different administrative accounts for my helpdesk / workstation administration for delegation and accountability, and if a normal user logged back in first, BLAMMO! Wiped out the install. 

Very weird update, but we can close the dang year so good enough.

Complete reinstall on server and 105 workstations, big PITA, and weird slowdown with My Assistant client included for free!

The new feature that updating the server updates the content of the WinInst installation at least worked, but that meant no scripting to distribute the patch at all.

40% of reinstalls failed for various reason, so a full install was required. I received no reports of the .DSK desktop configuration files changing, though, so there is that. 

Also, with many installs, after the installation is complete and the workstation reboots, the user account used for the upgrade MUST login again to let the installer scripts complete, or the start menu will be empty for the normal user of the workstation. I use different administrative accounts for my helpdesk / workstation administration for delegation and accountability, and if a normal user logged back in first, BLAMMO! Wiped out the install. 

Very weird update, but we can close the dang year so good enough.

Does anyone know - do you HAVE to install 17.1.8? We are currently on 17.1.6 and would rather not have to go through the hassle of installing if I don't have to. Is there anything critical between versions that would require an install before year-end processing?

Late to answer, sorry, but we specifically updated to 17.1.8 to close the year. That's the supported version and we try to do things by the numbers. We've learned not to give Support any wiggle room about things like that. 

Since people seem to successfully close the year with just updated tax tables, you might be able to get away with it, but.......

As far as I know, the update has nothing to do with closing the year. You have to run it before doing W2s though.