A group of Microsoft Products and technologies used for sharing and managing content, knowledge, and applications.
Hi Gabriella Barro,
Thank you for posting your query in our community.
Per your description, when you try to access a SharePoint page, an error will pop up.
There is a scenario is: The homepage of the SharePoint site might have been deleted.
Here is an official article provided detailed steps for this scenario, you can try it out to see the result: ERR_INVALID_RESPONSE error when accessing SharePoint site - SharePoint | Microsoft Docs
If the problem persists, please feel free to post back.
Best regards,
Jazlyn