Hi Andres,
Thanks for sharing your experience with us.
Regarding the authentification error when connecting PostgreSQL database in Excel, you may try following and see if it will help:
1.Refer to the Note inthis article and make sure you have installed the Ngpsql data provider for PostgreSQL installed on your computer
2.Click Data tab>Get Data>Data Source settings>Clear Permissions.
3.Or try running Excel in safe mode, then connect to the PostgreSQL database again.
Please also ensure to use the latest version of Office. Click File>Account>Update Options>Update Now, see if there is any update available.
If issue persists, please help confirm the following information. Appreciate your time and effort.
1.Please share with us a full screenshot of Product Information via File>Account.
2.What are your detailed steps before getting the error message.
Best Regards,
Tina
[Updated by Tina Chen MSFT, June 27, 4:22 AM (UTC)]