We upgraded from Confluence 6.13 to 7.9.18 by performing a second installation of Confluence and importing the database. When logging in and trying to access the list of spaces through the "Spaces DIrectory" link it says "An error occurred while searching for spaces."
After debugging the issue, I noticed that the UI is sending an AJAX request to the backend and getting XML as response, but it tries to parse it as JSON and errors out. The request header is actually for JSON, but the backend returns XML. HEADER ACCEPT is "application/json, text/javascript, */*; q=0.01"
What part of the upgrade process could have caused this, and what can I try to make the backend return JSON?
