I would make sure you ran the client install under the user's profile.  If that does not work you may need to run the \noprofile.  Go to the Knowledge Base at  www.SageKB.com and search on KB #55103 Error: "Unable to complete the startup of the Sage BusinessWorks product. The version of this workstation's Sage BusinessWorks client does not match the version of the server installation. Before you can run Sage BusinessWorks at this workstation, you must first install the 20xx.00 client. Please refer to your installation guide for complete instructions" after running the client setup.

Sincerely,

Coleen Graber

Coleen, thank you much for your reply!

We were able to get all but one workstation up and running with the 2020 update. We started the day with a chat with customer service, where after some initial troubleshooting,  we did the \no profile approach from the knowledge base article you shared (we'd done the first portion of the steps of delete and reinstall, prior to calling). What finally worked on all but one machine, was to use Windows add/remove programs on each workstation and on all profiles, then perform the run command string for the setup file, which would trigger the BW reinstall/uninstall pop-up. Both had to be done or we'd end up with the same error, as for whatever reason, it seems the Windows add/remove does not remove all files/conflicts. Once this was completed, we returned to our admin-level user profile, performed the client install according to KB #55103, attempted to launch and if successful, we'd move on to the standard user profile and perform the client install.

Typically an update, even with database conversion, has taken no more than 30 to 60-minutes for the server and all workstations to be brought back online. This round the server was complete in under 30 (time includes the pre-update backup, the update, the database conversions and post-update backup) and if the client installs had gone smoothly, it would've been under 5-minutes per workstation. Instead, we accumulated over 6-hours. That being said, I am happy that 99% of our workforce is able to fully use their system and will, one way or another, get the last workstation back online today.

Kim

Perfect - it sounds like you are on your way...just one ore left.  If you do get an error on that last workstation, one quick sources would be to continue to use our chat or search our Knowledge Base www.SageKB.com . We try and keep that updated, especially with installation questions. 

Sincerely,

Coleen

Last workstation has been updated and BWG is functioning properly. I don't know what "ghost" kept preventing us from having a successful install but not even going to give it another thought, as just so happy all is up and running.

I had done a search prior to contacting customer service, as I wasn't keen on having to wait until Monday when all expected to be able to work fully when they arrived, but didn't see a 2020 specific article, hence the post here and doing the steps I already knew to do from 20+ years of working with BWG (I used to be one of the beta testers who worked with Siobhan and Kim -- miss those times :) ) Which FYI, even customer service had to do some digging and "try this" vs concrete step by step resolution. Hopefully now if someone has a similar issue, they'll be able to quickly resolve :)