In order for WorshipTools to access SongSelect, the church needs to sign in to CCLI from within WorshipTools using a valid CCLI Profile login (email and password). These logins often belong to a specific individual that serves at the church. If that individual ever leaves their position, they may be removed from the CCLI user list. This is what causes the link from WorshipTools to CCLI to sever.
To fix this issue, you'll first need to be an Organization Administrator on the WorshipTools account. If you are not an Org Admin, please contact your Org Admin for help.
Click on the ⚙ gear icon in the top right corner of Presenter and select Settings. On the following page, open Connections from the left-hand menu. Disconnect SongSelect, then reconnect with an active SongSelect login for your church. Doing so will re-establish the connection between the two programs so that you can return to importing songs from SongSelect without issue. You can also fix this error in the Music Stand app.
For any SongSelect support, please contact CCLI directly.