Hello there,
Thank you for getting in touch with us about your issue.
Does this happen only when TranslatePress is activated on your website?
If you do not know the answer I recommend you start with a compatibility test.
Since this looks a lot like a conflict with some other code, the first/next recommended step is the conflict test (ideally in a staging environment):
??*Briefly* disable all other plugins and enable the default Twenty Twenty theme. Please also disable all add-ons. If this fixes the problem, as it probably will, enable everything one by one, checking each time to see when the problem returns.
Please let us know when you find the conflict so that we can take a look and see what we can do about it.
If that’s not it there is a chance that your hosting provider doesn’t allow our plugin to work with subdirectories. You should check this with your provider.
If that’s not it either, I found an article that is relevant to your issue that might help:
https://www.wpbeginner.com/wp-tutorials/how-to-fix-the-error-establishing-a-database-connection-in-wordpress/
Let me know how it goes or if you have any other questions.
