Attempting to upgrade Tableau from 2021.something to 2022.3.5 repeatedly failed with the following error in the upgrade log:

Failed with the error "Detected the old version of Tableau Server takes precedence on the system PATH".

 

And there were all sorts of things online to try — most of which involved changing the environment variables Tableau sets. But they weren’t wrong … or, rather, it was impossible to tell which was “right”: the new version I was trying to install or the old version that was still running. On a whim, I thought I’d try an admin-level command prompt. Opening the command prompt with the “Run as administrator” option allowed me to upgrade the server.

Except … I upgraded another server the next night. I knew to launch the command prompt in administrator mode, but I was incredibly dismayed to encounter the exact same error. Even using an admin level command prompt. Then it occurred to me — Windows evaluates the environment variables when you launch the shell (in fairness, every Unix/Linux variant I’ve encountered does the same thing). The installer must be changing the Tableau environment variables. If you use a command prompt that was open prior to running the installer … you don’t have the new values. You have the old ones — so the environment variable, as seen by the upgrade script, is pointing to an older version of Tableau. Launch a new command prompt, re-evaluate the environment variables, and the script now sees the proper version. Hopefully my next upgrade won’t include a panic inducing “yeah, that’s not gonna happen” error!