I googled and looked at many "Galaxy won't start"-Threads over the internet, but none of the proposed solutions worked for me, so I have to start my own unfortunately.

This is on Win 10.

Problem:
Galaxy does not start. Deinstall -> Clean -> Reinstall actually enables the app to start _once_, but after it is closed afterwards it can not be reopened until the next reinstall.

Observations:
Looking at the logs, I can see that the "GalaxyInitialization.log" is the only one getting updated when trying to start the app:
"Initialization strategy 'UpdaterPreventLaunchStrategy' returned exit code 'Client could not start because updater is running.'. The client will exit."

I can then kill the "Galaxy Updater" task in Task Manager and retry, then I see the "GalaxyClientService" and "Galaxy Updater" in my processes for a short time, until the "GalaxyClientService" disappears again. The app does not open. Log says:
"Initialization strategy 'InitClientStrategy' returned exit code 'Launching Updater; exiting.'. The client will exit."

Any more attempts to open Galaxy then lead to "Could not start because Updater is running" again.

Restarts don't work, reinstall only works for one launch of the application, after which it seems mucked up again. I tried cleaning the registry and restarting after each step of uninstall, cleaning ~User/Appdata/Local and ProgramData/GoG

Really not sure what more to try, any ideas are very welcome.

Dupe thread. We're following up here:

https://www.gog.com/forum/general/galaxy_wont_start_because_updater_is_running_restart_reinstall_registry_clean_wont_work