I've never seen that. I'd sooner suspect you misread the error message. You're supposed to manually launch the installer while GOG Galaxy isn't running. If you don't uninstall beforehand, nothing happens to your data. You can also manually back up the data folders before installing:
%ProgramData%\GOG.com\Galaxy\
%LocalAppData%\GOG.com\Galaxy\

The less you restore from those folders after an update, the better. At the very least avoid restoring the redists folder which contains outdated executables. Open a support ticket, if you haven't already. Tell the chatbot the problem is of type "other" twice to do so. Zip up the %ProgramData%\GOG.com\Galaxy\logs folder while GOG Galaxy isn't running and attach it to your ticket.

the app will not have permission but that could be Windows 11, you installed to program files or have some weird 3rd party software... who knows

it sucks because if galaxy flags the problem i would fix it. all i get is a failed update notification and a message to delete galaxy and install it again. too much of hustle really. i'll just avoid updates for a year or so.

for the data, all i meant was that i would have to select each game of reinstallation. no download is needed, the galaxy program just takes some time to recognize the files and ensure the game will be running. it's a hustle when you have a large collection of games.

Some people have written that the latest versions have fixed this longstanding issue. I haven't tried it, but up to now I've just realized that when Galaxy tells me an update is available and I feel like updating it, I needed to completely exit Galaxy, download the very small installer program from https://www.gog.com/galaxy, and install it from that. Always updates that way with zero problems, and it only takes like an extra minute to do it that way rather than doing it within the Galaxy program when that works.