I have published a Google Sheet addon to the Google Workplace Marketplace. Now I'm trying to update it. After deploying a new version (Version 26 in this case), I tried to update it on the Google Workplace Marketplace SDK, but it should the following error message:
Project Key is not associated with the current project or the script version doesn't exist.
Screenshot here
Place note that I used the same method and successfully updated the addon many times, but I just cannot do it today.
This has already been reported on Google's Issue Tracker here. I suggest you star (★) the issue and eventually add a comment saying that you are affected by it, as all the updates will be posted there.